541.If you use ALTER DISKGROUP ... ADD DISK and specify a wildcard for the discovery string, what
happens to disks that are already a part of the same or another disk group?
A. The command fails unless you specify the FORCE option.
B. The command fails unless you specify the REUSE option.
C. The command must be reissued with a more specific discovery string.
D. The other disks, already part of the disk group, are ignored.
Answer: D
答案解析：
参考：http://docs.oracle.com/cd/E11882_01/server.112/e18951/asmdiskgrps.htm#OSTMG10222
从以下两句话中，是否应该选A答案呢。
The following statement would fail because the search string matches disks that are contained in other disk groups. Specifically, /devices/diska4 belongs to disk group data1 and /devices/diskb4 belongs
to disk group data2.
If /devices/diskc3 was previously a member of a disk group that no longer exists, then you could use the FORCE option to add the disk as a member of another disk group. For example, the following use
of the FORCE clause enables /devices/diskc3 to be added to data2, even though it is a current member of data3. For this statement to succeed, data3 cannot be mounted.