Who is responsible for the gender of a new born baby a male or female​

just read my explanation :)

Explanation: Almost everyone has around a 50% chance of having a boy and a 50% chance of having a girl. What we can say is that dad's sperm determines whether a baby will be a boy or a girl. About half of his sperm will make a boy and half a girl. The sex of the baby depends on which sperm gets to the egg first.

because they want 2 and yea

this is math not biology xd