Which room in a bathhouse is equipped for oil and massage and is typically warm?

The tepidarium is indeed the correct choice as it serves the purpose of being a warm room in a bathhouse, specifically designed for oil application and massage. The tepidarium is characterized by its moderate heat, which makes it ideal for relaxation and preparing the body for hotter baths. It acts as a transitional space between the caldarium, which is hot, and the frigidarium, which is cold. The warm temperature helps to open up the pores of the skin, making it conducive for the application of oils and facilitating massage.

In contrast, the caldarium is focused on providing a hot environment, primarily for steam bathing, and would not be as suitable for oil applications and gentle massages. The frigidarium is designed for cold baths, meant to refresh the body after spending time in the hot areas and is not appropriate for warm activities or massages. Lastly, the palaestra is an exercise area rather than a bathing room, and while it might support physical activities related to fitness, it does not serve the needs of oil and massage as the tepidarium does.