Correct option is D
Given:
Symbols | + | × | ÷ | - |
Relations | Brother | Mother | Father | Sister |

A×B÷C-D+E-F → A is the mother of B, B is the father of C, C is the sister of D, D is the brother of E and E is the sister of F.

From the above family diagram, A is the Father's mother of F.
Correct answer is (d) Father's mother.