Test analysis: the antecedent of this sentence is related to the subject father of the next sentence, so whose is the leading word and who is it, choose D.

Comments: The usage of leading words in attributive clauses is complicated, and the key is to choose different leading words according to different antecedents. Note that the leading words used as preposition objects can only be in the objective case. It cannot be used in non-restrictive attributive clauses.