Two Containers of Equal Volume Are Connected by a Stopcock

Multiple Choice

Two containers of equal volume are connected by a stopcock as shown below.One container is filled with a gas at a pressure of 1 atm and temperature of 293 K while the other container is evacuated so that it is under vacuum.The containers are thermally isolated from the surrounding so no heat enters or escaped from the system.The stopcock is then opened allowing the gas from one container to fill the other.What is the final temperature of the gas after it has come to equilibrium?

A) 136.5 K
B) 273 K
C) 293 K
D) 195 K
E) undetermined