Which sentence uses parentheses to insert nonessential information?

• A. The plan will go ahead (which was approved).
• B. The plan which was approved (will go ahead).
• C. The plan (will go ahead) which was approved.
• D. The plan (which was approved) will go ahead.

Answer: (D)

The sentence is testing how to insert nonessential information using parentheses to set off a relative clause that describes a noun. The nonessential information here is the clause which was approved, and it adds extra detail about the plan without changing the main claim.

Because this extra detail isn’t essential to understanding the sentence, it should attach directly to the noun it describes and be set off in a way that marks it as optional. The correct form places the parenthetical right after the noun: The plan (which was approved) will go ahead. If you remove the parenthetical, the core meaning remains intact: The plan will go ahead. The punctuation with parentheses keeps the sentence clean and makes the extra information clearly optional.

Other options misplace the modifier or disrupt the sentence structure. Placing the parentheses after the verb separates the descriptive clause from the noun it should modify, making the sentence feel off. Using a restrictive sense of which (without proper nonessential punctuation) changes meaning, and putting the entire predicate in parentheses breaks the sentence flow.