A, B, C, D, E and F are six members in a family. The family consists of two married couples. The family members are a lawyer, teacher, businessman, engineer, accountant and doctor. A, the lady teacher, is married to the businessman. The lawyer is married to B, who is a doctor. F, the accountant, is the son of B and the brother of E. C, the lawyer, is the daughter-in-law of A. E is the unmarried engineer. A’s son’s son is F. How is D related to F?