What does "caustic" mean in terms of tone?

The term "caustic" in the context of tone refers to something that is harsh or corrosive. It often describes a manner of speaking or writing that is biting, sharp, or critical, potentially causing emotional pain or damage, much like a substance that can corrode or burn when it comes in contact with skin. A caustic tone may be used in sarcasm, criticism, or ridicule. This makes it distinct from tones that evoke warmth, support, or uncertainty. The other options reflect tones that are positive or neutral rather than harsh or critical, which aligns with the definition of "caustic."