If a substance '$$A$$' dissolves in solution of a mixture of '$$B$$' and '$$C$$' with their respective number of moles as $$n_A$$, $$n_B$$ and $$n_C$$, mole fraction of $$C$$ in the solution is:

A

$$\frac{n_C}{n_A \times n_B \times n_C}$$

B

$$\frac{n_C}{n_A + n_B + n_C}$$

C

$$\frac{n_C}{n_A - n_B - n_C}$$

D

$$\frac{n_B}{n_A + n_B}$$