A + B means, A is the sister of B.

A - B means, A is the daughter of B.

A×B means, A is the brother of B.

A÷B means, A is mother of B.

If X + Y ÷ Z × P ÷ Q - R, then how R is related to Y?

Daughter's husband

Note:

↑ or ↓ ⇒ Upward or downward line shown "generation gap" .

   =    ⇒ Double lines shown "relation b/w Husband & Wife"

   —   ⇒ single line shown "relation between them other than Husband & Wife".

Clearly, (c) is correct answer.