One more Science question!!?

Question

The Smith's have four children, all girls. Their fifth child is a boy. Why did this change occur?

A) The "law of averages" finally catching up.

B) The conception classes taken by the parents.

C) The father's contribution of the Y chromosome.

D) The mother's contribution of the Y chromosome.

E) The timing of the fertility cycles.

Answer 1

C) The father's contribution of the Y chromosome.

Answer 2

c 4 sure

Answer 3

C)!!!

I'm possitive

Answer 4

The s*x of a baby is determined by the father.  The father makes "X" sperm and "Y" sperm.  Whichever one gets there first determines the s*x of the baby.