Given the Reaction A(g) + B(g) C(g) + D(g)

Given the reaction A(g) + B(g) C(g) + D(g) . You have the gases A, B, C, and D at equilibrium. Upon adding gas A, the value of K

A) increases because when A is added, more products are made, increasing the product-to-reactant ratio
B) decreases because A is a reactant, so the product-to-reactant ratio decreases
C) does not change because A does not figure into the product-to-reactant ratio
D) does not change as long as the temperature is constant
E) depends on whether the reaction is endothermic or exothermic