531.When starting up your ASM instance, you receive the following error: What is the cause of the error?
A.The ASM_DISKGROUPS parameter is configured for three disk groups: DGROUP1, DGROUP2, and DGROUP3. The underlying disks for these disk groups have apparently been lost.
B.The format of the ASM_DISKGROUPS parameter is incorrect. It should reference the disk group numbers, not the names of the disk groups
C.The ASM_POWER_LIMIT parameter is incorrectly set to 1. It should be set to the number of disk groups being attached to the ASM instance.
D.The ASM_DISKSTRING parameter is not set; therefore disk discovery is not possible.
E.There is insufficient information to solve this problem.
正确答案是D