Chances for a son or daughter in each birth is

3:1 between son and daughter

1:3 between son and daughter

1:1 between son and daughter

None of the above

Explanation

The sex of a baby is determined by the sperm that fertilizes the egg.

If the sperm carries a Y chromosome, the baby will be a son.

If the sperm carries an X chromosome, the baby will be a daughter.

Since the chances of receiving a Y or an X chromosome are roughly equal, the probability of having a son or a daughter is approximately 50/50, or 1:1.