A x B means A is the father of B. Which of the following means that C is the son of M?

N + M - F x C

M x N - C + F

M - N x C + F

F - C + N x M

M x N → M is the father of N

N - C → N is the sister of C

and C + F → C is the brother of F.

Hence, M is the father of C or C is the son of M.