Which statement correctly describes the relationship between heat and temperature?

The correct choice highlights that temperature is fundamentally a measure of the average kinetic energy of the molecules in a substance. This means that temperature quantifies how fast the molecules are moving; higher temperatures indicate faster molecular motion, while lower temperatures indicate slower motion.

In the context of thermal energy, while heat refers to the total energy transferred due to temperature differences (which involves both kinetic and potential energy at the molecular level), temperature solely reflects the energy associated with the motion of the molecules. Therefore, understanding temperature as a measure of molecular kinetic energy helps clarify how it is distinct from concepts like heat, which encompasses a broader range of energy.

The other options do not accurately capture this relationship. One suggests that temperature measures total energy, which is misleading as it ignores other forms of energy present in a substance. Another proposes that heat can be contained while temperature cannot; this statement is less clear as both can be understood in terms of specific systems but do not have a straightforward relationship. Lastly, suggesting that heat and temperature are the same concept is incorrect as they are related but fundamentally different phenomena in thermodynamics.