question_answer

There are four objects A, B, C and D. It is observed that A and B are in thermal equilibrium and C and D are also in thermal equilibrium. However, A and C are not in thermal equilibrium. We can conclude that -

A)  B and D are in thermal equilibrium

B)  B and D could be in thermal equilibrium but might not be A and D

C)  B and D cannot be in thermal equilibrium  

D)  the zeroth law of thermodynamics does not apply here because there are more than three objects