Final answer:
Heat flows from an object at a higher temperature to an object at a lower temperature, regardless of the states of the objects. Therefore, statements A, B, and C are all true.
Step-by-step explanation:
Heat flows from an object at a higher temperature to an object at a lower temperature. This means that statement A is true.
Heat can flow between objects in different states, such as from an object in liquid state to an object in solid state. So statement B is also true.
Heat flows from an object with higher thermal energy to one with lower thermal energy. Therefore, statement C is true.
In summary, statements A, B, and C are all true. The correct answer is Option 2: A and C only.