Final answer:
The correct answer to the student's question is c) Cadaverous. This word is used when a person is treated like or resembles a corpse.
Step-by-step explanation:
The student asked for the word that describes a decedent being treated like a corpse by others. The correct option among the provided choices is c) Cadaverous. The term cadaverous is used to describe someone who looks corpse-like, suggesting that individual is being treated or appears as a corpse would. The other options have different meanings: a) Posthumous refers to something occurring after a person's death, b) Antemortem pertains to the period before death, and d) Deceased means that the person has passed away.