Question

what is heat?
loss of energy between two objects with unequal temperatures.
when energy is created
the flow of energy between two objects of unequal temperature
when energy is destroyed

Explanation:

Heat is defined as the flow of energy between two objects with unequal temperatures. According to the first law of thermodynamics, energy cannot be created or destroyed (so options about energy creation or destruction are wrong). And it's not just a "loss" but a flow of energy.

Answer:

The flow of energy between two objects of unequal temperature