Select all of the true sentences.

Parentheses enclose added material.
Parentheses enclose numerical figures that confirm written numbers.
Parentheses are always used for numbers in lists of words or ideas.
Parentheses enclose explanatory material.
Parentheses are used to set off main ideas.
A parenthetic expression is a group of words that is not closely related to the rest of the sentence.

Following sentences are true-

Explanation:

Parentheses is an explanatory word or sentence that is being inserted in any article, story, or passage. Parentheses are usually marked by brackets (round or box) or in some cases even dashes.

For example: She finally answered (after taking ten minutes to think) that she did not understand the question. Parentheses helps the writer to provide or add an additional information, which they otherwise can't.

it's either a or b. i'm leaning more towards a.

do you have more to the question?