Which statement about a retronym is correct?

• A. A retronym uses the original term after a newer version appears.
• B. A retronym is a synonym with variant spelling.
• C. A retronym is a name given to distinguish an older form when a newer version exists, e.g., 'acoustic guitar' after 'electric guitar.'
• D. A retronym is any term borrowed into another language.

Answer: (C)

Retronyms are names created to distinguish an older form once a newer version exists. They usually attach a descriptor to the base term, signaling that what used to be simply called by a single name now has a newer version to compare with. For example, after electric guitars became common, people started saying “acoustic guitar” to refer to the older, non-electric version. That added word makes it clear which form is being talked about.

This fits best because it captures the purpose and pattern of retronyms: naming the older form in contrast to a newer one, rather than just using the original term after the fact or treating it as a simple spelling variant. The other statements miss that distinguishing feature, or describe things that aren’t how retronyms work.