To solve this analytical ability question, we need to determine the relationship step-by-step:
Your Mother’s Maternal Aunt:
This person is your mother’s mother’s sister. Therefore, she is your mother’s maternal aunt.
Your Mother’s Maternal Aunt’s Only Niece:
The only niece of your mother's maternal aunt would be your mother, since the niece is the daughter of the aunt's sibling, and there is only one niece mentioned, which corresponds to your mother.
Your Mother’s Father:
Since your mother is the only niece in this context, the father of your mother is your grandfather.
Conclusion:
Therefore, your mother’s maternal aunt’s only niece’s father is related to you as your grandfather.
Thus, the correct answer is Grandfather.
Let’s rule out other options to ensure the accuracy of this conclusion:
Uncle: An uncle would be either a brother of your parent or the husband of your aunt. This does not fit as the specified person is the father of your mother.
Father: The question leads to the grandfather, and for the person to be your father, the description should directly link to your father, which it does not.
Cousin: A cousin refers to the children of your parents' siblings; this is not relevant to the relationship described.