Question

which chromosome combination will make a baby boy?

Explanation:

In humans, biological sex is determined by the sex chromosomes. Females have two X chromosomes ($XX$), and males have one X and one Y chromosome ($XY$). The sperm can carry either an X or a Y chromosome, while the egg always carries an X chromosome. If a sperm with a Y chromosome fertilizes an egg (which has an X chromosome), the resulting combination is $XY$, which develops into a male.

Answer:

The chromosome combination $XY$ will make a baby boy.