|A) Father||B) Grandmother|
|C) Grandfather||D) Grandfather or Grandmother|
Answer: D) Grandfather or Grandmother
S is daughter of P and sister of T. So, T is daughter of P.
Now, the sister of P is the daughter of M. This means that P is also the daughter of M. Clearly, T is the granddaughter of M.
So, M is the Grandfather or Grandmother of T.