Correct option is B
Given:
R is the sister of S.
J is the mother of R.
I is the husband of J.
T is the daughter of I.
D is the mother of J.
C is the father of T's mother.

From the given information relationship diagram will be:

So, D is T's Mother's mother.
Final Answer:
Mother’s mother
Mother’s mother
Final Correct Option:
(b)
(b)