Correct Answer: P – Q × R

Solution : Let's check the given options –
First option: P – R × Q
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female. From the above family tree, it is evident that the gender of Q is not definite. Q can either be the son or daughter of P.
Second option: Q – P × R
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female. From the above family tree, it is evident that Q is the mother of P.
Third option: P – Q – R
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female. From the above family tree, it is evident that Q is the daughter of P.
Fourth option: P – Q × R
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female. From the above family tree, it is evident that Q is the son of P.

So, only the fourth option fulfils the relation given in the question. Hence, the fourth option is correct.