Given the following parallel reactions, where $\large\frac{k_1}{k_2}=\frac{1}{3}$. Initially only 4 moles of A are present. The total number of moles of A,B & C at the end of 50% reaction is:

Question

$(a)\;2\qquad(b)\;4\qquad(c)\;5\qquad(d)\;3$