Need Help with Predicate Logic( True Or False)

In which situation a is definitely true, and do the same for b
a. ∀x(Bx →∃y(Gy ^ Kxy))
b. ∃y(Gy ^∀x(Bx → Kxy))

A:every boy kissed Mary, and no body kissed any other girl
B:every boy kissed the girl that he likes best
C:every boy kissd Mary,and every boy also kissed Sue, but no boy kissed any other girl(s).

I think I haven’t fully mastered predicate logic and it is my biggest nightmare…....
I think that a is true in B, and b is true in C, well I don’t know just a guess…............ HELP!!!