Correct Answer: P @ Q & R # S

Solution : Given:
A @ B means A is the husband of B.
A & B means A is the mother of B.
A # B means A is the wife of B.

Now, let's check the options –
First option: P @ Q & S # R

From the above family tree, it shows that P is the father of S.

Second option: Q @ P & R # S
According to the given information, the family tree will be –

From the above family tree, it shows that P is the mother-in-law of S.
Third option: P @ Q & R # S
According to the given information, the family tree will be –

From the above family tree, it is evident that the P is the father-in-law of S.
Fourth option: P @ Q & R & S
According to the given information, the family tree will be –

Here, the quadrilateral represents the male and the circular figure represents the female in the figure.
From the above family tree, it shows that P is the grandfather of S.

So, only the third option fulfils the relation as per the family tree. Hence, the third option is correct.