033 有一道题不太明白的题

Which two statements are true with respect to hash clusters? (Choose two) A. Hash clusters perform well when the cluster keys are updated rarely. B. Hash clusters perform well when the cluster keys are updates frequently. C. Use of hash clusters may be beneficial for a data warehouse type of application. D. Full table scans are generally faster on clustered tables than on non-clustered tables. E. If an application mostly issues range searches, hash key is usually found in a single read while a nonclustered table with an index requires a minimum pf 2 I/O’s 我觉的是 A ，E 不知对不对