The diagram below shows two substances, A and B, which are at different temperatures. What will happen when substance A is dropped into substance B? a Substance A and B will eventually reach the same temperature. b Substance A will get even warmer as heat flows into it from substance B. c Substance A and B will exchange heat, and they both will reach 25°C. d Substance A and B will exchange heat, and they both will reach 50°C.

a Substance A and B will eventually reach the same temperature.

Not enough information is given for other choices.

Correct, the only information given is that substance A and substance B are at different temperatures. Without any other information, the most reasonable assumption is that they will eventually reach the same temperature through heat exchange. Other options cannot be determined without additional information.