In a family of six (A, B, C, D, E, F), there are two married couples.
B, a doctor, is the father of E.
F is the grandfather of C and works as a contractor.
D is the grandmother of E and is a housewife.
The family has one doctor, one contractor, one nurse, one housewife, and two students.
Based on this information, who is the mother of C?
