Harry is the husband of Eli and Sue is the sister of Christa's father and Fred is the father of Sue. Nichole is Eli's mother-in-law and Fred is the husband of Eli's husband's mother. Sue is the sister-in-law of Eli who is the only child of her parents. If Nichole has only two children, then how is Fred related to Christa?

A

Paternal grandfather

B

Maternal grandfather

C

Paternal uncle

D

Maternal uncle