Which of the following is true of an index used to support a UNIQUE constraint?
A. It must have the UNIQUE attribute.
B. It cannot be created explicitly by the user.
C. It must have the UNIQUE and CLUSTER attributes.
D. It must have the UNIQUE WHERE NOT NULL attribute.
Answer:A
Which of the following is true of an index used to support a UNIQUE constraint?
A. It must have the UNIQUE attribute.
 B. It cannot be created explicitly by the user.
 C. It must have the UNIQUE and CLUSTER attributes.
 D. It must have the UNIQUE WHERE NOT NULL attribute.
