6609. Slangs in a language are usually ephemeral in nature.

✅ The correct answer is option A.
Transient : lasting only for a short time; impermanent.

Customary : according to the customs or usual practices associated with a particular society, place, or set of circumstances.

Necessary : needed to be done, achieved, or present; essential.

Obvious : easily perceived or understood; clear, self-evident, or apparent.

Ephemeral : lasting for a very short time.

Synonym of Ephemeral is Transient