The term that describes two or more objects in a system reaching the same temperature is

The correct answer is Thermal Equilibrium

Explanation:

The term "thermal equilibrium" is used when two or more objects have the same temperature and therefore there is not an exchange of heat between them. This occurs when the objects had a different temperature at the beginning but due to a close contact heat is transferred from one object to the other until an equilibrium or same temperature is reached. For example, a hot cup over a table or any other surface will transfer the heat to the surface, but after some time both the cup and the surface will have the same temperature or will reach thermal equilibrium.

if you mean hydrogen and oxygen then water is the product

i think it's letter a.