In which scenarios will heat flow from Object 1 to Object 2?

Heat will flow from Object 1 to Object 2 when there is a temperature difference between the two objects, with heat moving from the hotter object (higher temperature) to the cooler object (lower temperature) until thermal equilibrium is reached.

In examples 1, 2, and 4, this principle can be applied successfully. If, for instance, Object 1 is at a higher temperature in each of these examples, then it will transfer heat to Object 2. The transfer can occur through conduction in direct contact or through convection if the surrounding medium is involved.

In example 1, if Object 1 is significantly hotter than Object 2, heat will readily flow from Object 1. Example 2 might illustrate a scenario with convection, where the movement of fluid carries heat from Object 1 to Object 2, while in example 4, another mechanism (such as radiation or conduction) could also result in heat flow depending on the relative temperatures of the objects in question.

While the other combinations may miss one or more of these examples where heat transfer is indeed occurring, option C correctly identifies all the instances where Object 1 is transferring heat to Object 2.