The correct answer is option 1, XY. In humans, sex is determined by the combination of sex chromosomes inherited from the parents. Men have one X chromosome and one Y chromosome, while women have two X chromosomes. The presence of the Y chromosome in men determines their development into males.
Option 2, XX, is incorrect because this represents the pair of sex chromosomes in women, not men. Women have two X chromosomes.
Option 3, YY, is also incorrect because YY is not a viable combination. It would result in a genetic abnormality and is not found in humans.
Option 4 states that no option is correct, but this is incorrect as option 1, XY, is indeed the correct answer.