X and Y are two sets and f:X→ Y .If f(c)={y; c is subset ofX , y is subset of Y} and f-1(d) = {x;d is subset of Y,x is subset of X}, then the true statement is
A) f(f-1(b)) = b
B) f(f-1(b)) = b,b is subset of Y
C) f-1(f(a)) = a
D) f-1(f(a)) = a,a is subset of X
X and Y are two sets and f:X→ Y .If f(c)={y; c is subset ofX , y is subset of Y} and f-1(d) = {x;d is subset of Y,x is subset of X}, then the true statement is
A) f(f-1(b)) = b
B) f(f-1(b)) = b,b is subset of Y
C) f-1(f(a)) = a
D) f-1(f(a)) = a,a is subset of X