Ammonium hydrogen sulfide, NH4HS, is unstable at room temperature and decomposes: You have placed some solid ammonium

Question:

Ammonium hydrogen sulfide, NH4HS, is unstable at room temperature and decomposes:

You have placed some solid ammonium hydrogen sulfide in a closed flask. Which of the following would produce less hydrogen sulfide, H2S, which is a poisonous gas?
a. Removing some NH3 from the flask
b. Adding some NH3 to the flask
c. Removing some of the NH4HS
d. Increasing the pressure in the flask by adding helium gas Explain each of your answers.