Final answer:
The correct term for a substance that produces insensitivity to pain by inducing a temporary loss of sensation or awareness is anesthesia.
Step-by-step explanation:
An anesthetic is a medication or other substance that produces a temporary loss of sensation or awareness. When it comes specifically to pain, the term we are looking for is anesthesia, not to be confused with analgesia, which is the relief from pain without the loss of consciousness, or with euphoria or paralysis, which have different meanings entirely. An anesthetic can be classified as either general or local. General anesthetics induce a loss of consciousness and a general insensitivity to feeling or pain, as seen with substances like diethyl ether and ketamine. Therefore, the correct answer to the question is: c) Anesthesia.