C I’m not 100% sure but if it’s wrong sorry
A backboard could mean:
a board placed at or forming the back of something, such as a collage or piece of electronic equipment.<span>
an upright board behind the basket, off which the ball may rebound.
a board used to support or straighten a person's back, especially after an accident.
It depends on the context of the word.
</span>
Answer:
The past participle is used with the verb (have / has / had) to create the present and past perfect tenses. The past participle form is also used to modify nouns and pronouns.
Explanation: