Q10,p3,d14. Let R = ABCDE is a relational scheme with functional dependency set F = {A →B, B →C, AC →D}. The attribute closures of A and E are

(A) ABCD, φ

(B) ABCD, E

(C) Φ, φ

(D) ABC, E

Answer B.

A->B,B->c,then A->C.

AC->D ,if we know A then we can find out unique value of C. so from A we can find out value of D.

from A we can findout A,b,c,d, where as from E we can find out E only.