Which of the following statements about sex determination is correct? At fertility

A.

the probability of male to female offspring is 1/2

B.

the Y chromosome of the father decreases the probability of having a male child to 3/4

C.

the xx chromosome of the mother decreases the probability of having a female child to 3/4

D.

the vigour of either parents determines the sex of the offspring

Correct answer is A

No explanation has been provided for this answer.