Which law of thermodynamics would be violated if heat were to spontaneously flow between two objects of equal temperature?

Actually the second law of thermodynamics would truly gets violated ie, which means that the entrophy changes of the isolated system can never be negative, which covers the above that if heat were to spontaneously flow between any two objects of equal temperature would be fully violated.

That would be the corect answer hope this

Your answer is 1.5 hope i