Linked List in C (2Shopping Cart)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

/*
 * Item struct for holding item information
 */
typedef struct _Item
{
    char name[25];
    size_t quantity;
    double price;
    struct _Item *next;    
}Item;

/*
 * ResizeArray will be called when the number of
 * items to be added to cart exceed the current bounds of the array
 */
void ResizeArray(Item **ShoppingCart,int num)
{    
    Item *temp = *ShoppingCart;
    *ShoppingCart = malloc(num*2*sizeof(Item));
    if(*ShoppingCart == NULL)
    {
        printf("Cart can't add more items. \n");
        return;
    }
    memmove(*ShoppingCart,temp,num);
}

/*
 * Print the current list of items
 */
void print_items(Item *head)
{
    Item *temp = head;
    while( temp != NULL)
    {
        printf("Item Name:%s \n",temp->name);
        printf("Item quantity:%lu \n",temp->quantity);
        printf("Item price:%.2f\n\n",temp->price);
        temp = temp->next;
    }
}

/*
 * Add an item to ShoppingCart
 */
void add_item(Item **head,Item *newItem)
{
    if(*head == NULL)
    {
        *head = newItem;
    }
    else 
    {
        Item *temp = *head;
        while(temp -> next != NULL)
        {
            temp = temp->next;
        }
        newItem->next = temp->next;
        temp->next = newItem;
    }    
}

/*
 * Provide a menu that allows the user to choose among 3 options.
 */
void menu(char* choice)
{
    char Buffer[50];
    printf("Enter a or A: Add an item to ShoppingCart\n");
    printf("Enter p or P: Print the current list of items\n");
    printf("Enter q or Q: Quit the program\n");
    printf("Enter your choice:");
    fgets(Buffer,50,stdin);
    sscanf(Buffer,"%c",choice);
}

int main()
{
    int num;
    int num_in_cart = 0;
    Item *ShoppingCart;
    Item *head = NULL;
    char Buffer[50];
    char choice;
    
    /*
      * Ask the user for the number of items,
      * and use this number as tbe initial size of cart
      */     
    printf("Enter the number of items you want to buy:");
    fgets(Buffer,50,stdin);
    sscanf(Buffer,"%d",&num);
    
    ShoppingCart = malloc( num*sizeof(Item) );
    if(ShoppingCart == NULL)
    {
        printf("ShoppingCart is NULL!\n");
        exit(1);
    }

    /*
      * Option A: Add am item to cart
     * Option P: Print the current list of items
     * Option Q: Quit the program
     */         
    menu(&choice);    
    while(choice != 'q' && choice !='Q')
    {    
        if(choice == 'A' || choice == 'a')
        {
            char Buffer[50];
            Item *newItem;
            if(num_in_cart == num)
            {    
                ResizeArray(&ShoppingCart,num);
                num = num*2;
            }
            
            newItem = &ShoppingCart[num_in_cart];
            newItem->next = NULL;

            printf("Enter name:");
            fgets(Buffer,50,stdin);
            sscanf(Buffer," %s",newItem->name);
            
            printf("Enter quantity:");
            fgets(Buffer,50,stdin);
            sscanf(Buffer,"%lu",&(newItem->quantity) );

            printf("Enter price:");
            fgets(Buffer,50,stdin);
            sscanf(Buffer,"%lf",&(newItem->price));

            printf("name = %s \n", newItem->name);
            printf("quantity = %lu \n", newItem->quantity);
            printf("price = %f \n", newItem->price);

            add_item(&head,newItem);
            num_in_cart++;

            menu(&choice);    
        }
        else if(choice == 'p' || choice == 'P')
        {
            print_items(head);
            menu(&choice);    
        }
        else
        {
            printf("Invalid input! \n");
            menu(&choice);
        }
    }

    free(ShoppingCart);
    printf("Program Exited.\n");
    return 0;
}