For a gaseous reversible reaction $A_{\left(g\right)}\rightleftharpoons 2B_{\left(g\right)}$ occurs in a closed vessel with movable piston, following graph was given.

By observing the graph , predict the correct change at 10 Minutes time. 

Additional amount of gas –A was added to the vessel at constant temperature and pressure

An inert gas was added to the vessel at constant temperature and volume.

Additional amount of gas –B was added to the vessel at constant temperature and pressure

An inert gas was added to the vessel at constant temperature and pressure.