To determine how D is related to B, let's break down the relationships as given in the question:
- B is the brother of S.
- S is the sister of F.
- D is the daughter of F.
From this information, we can conclude the following:
- B, S, and F are siblings, with B being the brother, and S and F being sisters.
- D, being the daughter of F, is the niece of both F's siblings (S and B).
Therefore, the relationship of D to B is that D is B's niece.
Let's analyze the options:
- Daughter: Not applicable, as there is no indication that D is the daughter of B.
- Sister: Not applicable, since the question states D is the daughter of F, and B is F's sibling, making them aunt/uncle and niece.
- Niece: This is the correct relationship, as explained above.
- Daughter-in-law: Not applicable, as there's no information about marital relationships for D or B.
Thus, the correct answer is Niece.