Final answer:
Room temperature egg whites achieve a greater volume when whipped compared to cold egg whites, since the proteins are more flexible and can form a better network to trap air.
Step-by-step explanation:
Room temperature egg whites whip to a larger volume than cold egg whites. The proteins in egg whites are more flexible at room temperature, which allows them to unfold more easily when whipped. This unfolding is crucial for forming the network that traps air and creates a foam. Therefore, room temperature egg whites can incorporate more air and achieve a greater volume. It's important to ensure that the bowl and beaters are clean and free of any fat, which can inhibit foam formation. The correct answer to the question is b) Room temperature egg whites.