f and h are function from A `rarr` B, where A = {a, b, c, d} and B = {s, t, u} defined as follows
f(a) = t, f (b) = s, f(c ) = s
f(d) = u, h(a) = s, h(b) = t
h(c ) = s, h(a) = u, h(d) = u
Which one of the following statement is true?