11. Gas in a chamber passes through the cycle ABCA as shown in the diagram above. In the process `AB,12` joules of heat is transferred to the gas. In the process BC, no heat is exchanged with the gas. For the complete cycle ABCA , the work done by the gas is 8 joules. How much heat is added to or removed from the gas during process CA?
(A) 20 J is removed.
(B) 4 J is removed.
(C) 4 J is added.
(D) 20 J is added.