sql server有多种选择

Question

关于索引

，以下哪三项是正确的

(A)Indexes speed up data access
(B)Indexes enforce uniqueness of rows
(C)Indexes incur no extra overhead
(D)Clustered indexes consume no extra disk space
(E)Non-Clustered indexes consume no extra disk space

我认为A，E，B有人同意吗？