Three identical metal blocks A, B, and C, each of mass 1kg and the same specific heat capacity, are thermally isolated from the environment. Initially the blocks have temperatures TA=400K, TB=300K, and TC=200K. At time t1 blocks A and B are placed in thermal contact and allowed to reach a common temperature T1. At a later time t2, block C is also brought into contact with A and B, and all three blocks eventually reach a final common temperature Tf.
Let S0 be the total entropy of the three–block system before any blocks are in contact, S1 the total entropy just after A and B reach temperature T1, and S2 the total entropy after all three blocks reach Tf. Which of the following correctly ranks these three entropy values?
(a) S0=S1<S2
(b) S0<S1=S2
(c) S0<S1<S2
(d) S0=S1=S2