Answer:
B) The entropy is greater in the second state, with the gas on both sides of the box.
Step-by-step explanation:
As we know that ,this is a irreversible process .The process leaves some effect on the surrounding or on the system itself ,is known as irreversible process.But on the other hand those process does not leave any effect on the system and surrounding is known as reversible process.
The entropy in the irreversible process always increases ,that is why the the entropy will be more when gas occupy the both boxes.
Therefore the answer is --B