Select the right option from the given alternatives. What is my father's…

Concept

In a blood-relation chain, decode one kinship link at a time, starting from the first named relative and building outward as a small family tree. Each link's gender and generation position fixes the next person's place in the tree; skipping or reordering a link mis-places the generation and produces the wrong kinship term for the final relative.

Step-by-step application

1. "My father's wife" = my mother, since no other wife is mentioned in the question.

2. "My mother's grandfather" = my great-grandfather.

3. "My great-grandfather's only child": since he has only one child, that child must be one of my mother's own parents — my maternal grandfather or grandmother, whichever line it is.

4. That parent's "son" = my mother's brother — my maternal uncle (true whether the parent traced in the previous step is my maternal grandfather or grandmother).

5. "My maternal uncle's daughter": a person in my own generation, the child of my parent's sibling.

Cross-check

Redraw the tree top-down: great-grandfather -> only child (one of my mother's parents) -> son (my maternal uncle) -> daughter. The final node sits one generation below my parent's generation and is reached through a parent's sibling's child — exactly the definition of a cousin, confirming the chain independently of how it was first traced.

Why the other options don't fit

• Aunt would follow only from mislabeling the "only child's son" as a daughter instead — that link is explicitly a son (my maternal uncle), and the chain still has one further step (that son's daughter) after it.

• Niece would require one of the links to be my own sibling's child — but every link in this chain runs through my mother's side, never through a sibling of mine.

• "Real" does not name a relationship produced by any of the five links at all.

Result

Therefore, my father's wife's grandfather's only child's son's daughter is my Cousin.