Which among the following determines the sex of the child ?

Sex chromosomes of father .

The sex of a child is determined by the "Sex chromosomes of father."

In humans, sex is determined by the combination of sex chromosomes inherited from both parents. The sex chromosomes are designated as X and Y. Females have two X chromosomes (XX), and males have one X and one Y chromosome (XY).

During fertilization, the father contributes either an X or a Y chromosome to the offspring through the sperm. The mother always contributes an X chromosome through the egg. The combination of the sex chromosomes received from both parents determines the sex of the child.

If the child inherits an X chromosome from the father, the combination is XX, and the child will be female. If the child inherits a Y chromosome from the father, the combination is XY, and the child will be male.

Therefore, the sex chromosomes of the father play a crucial role in determining the sex of the child.