Consider the Following Reaction at a Certain Temperature

Consider the following reaction at a certain temperature:
PCl₅(g) →PCl₃(g) + Cl₂(g)
K_c = 0.100
At equilibrium,[PCl₅] = 2.00 M and [PCl₃] = [Cl₂] = 1.00 M.If suddenly 1.00 M PCl₃(g) and Cl₂(g) is added,what is the equilibrium concentration of PCl₅(g) ?

A) essentially 4.00 M
B) 0.58 M
C) 2.58 M
D) 3.42 M
E) 1.42 M