Answer question numbers (a) - (d) on the basis of your understanding of the following paragraph and the related studied concepts :
Different species use very different strategies for this. Some rely entirely on environmental cues. Thus, in some animals like a few reptiles, the temperature at which fertilised eggs are kept determines whether the animals developing in the eggs will be male or female. In other animals, such as snails, individuals can change sex, indicating that sex is not genetically determined. However, in human beings, the sex of the individual is largely genetically determined. In other words, the genes inherited from our parents decide whether we will be boys or girls. But so far, we have assumed that similar gene sets are inherited from both parents.
How is sex determined in human beings ?

Explanation

In human beings, sex is determined by the chromosomes of sperms as they carry any one of the two different types of sex chromosomes.