Assertion: Two systems which are in thermal equilibrium with a third system are in thermal equilibrium with each other.
Reason: Heat flows spontaneously from a system at a higher temperature.
A) Both assertion and reason are true, and the reason is the correct explanation of the assertion.
B) Both assertion and reason are true, but the reason is not the correct explanation of the assertion.
C) Assertion is true, but the reason is false.
D) Assertion is false, but the reason is true.
