Methanol Can Be Synthesized by Combining Carbon Monoxide and Hydrogen

Methanol can be synthesized by combining carbon monoxide and hydrogen. CO(g) + 2H₂(g) ⇄ CH₃OH(g)
A reaction vessel contains the three gases at equilibrium with a total pressure of 1.00 atm. What will happen to the partial pressure of hydrogen if enough argon is added to raise the total pressure to 1.4 atm?

A) The partial pressure of hydrogen will decrease.
B) The partial pressure of hydrogen will increase.
C) The partial pressure of hydrogen will be unchanged.
D) K _p needs to be known before a prediction can be made.
E) Both K _p and the temperature need to be known before a prediction can be made.