To answer the following question, use the information given below.
i. There are six persons A, B, C, D E and F in a family.
ii. There are two couples in the group.
iii. A is the father of C who is a doctor.
iv. E is the son of C.
v. F is the grand daughter of D.
vi. The father of F is B, who is a professor.
vii. E and F are unmarried.
Who is the grandmother of E ?

A

C

B

D

C

B

D

None of these