Question

which word could best replace pointless without changing the meaning of the sentence? trying to keep our sand castle from being destroyed as the tide came in proved to be pointless.
plaintive
incongruous
futile
amorphous

Explanation:

"Pointless" means having no purpose or result. "Futile" also means incapable of producing any useful result; pointless. "Plaintive" means sounding sad and mournful. "Incongruous" means not in harmony or keeping with the surroundings or other aspects of something. "Amorphous" means without a clearly defined shape or form.

Answer:

C. futile