Which of the following options does not use parentheses correctly?

a. As more and more people started wearing masks, some others (or at least it seemed that way) became resistant to the idea.

b. The decision to cancel the event (due to the weather) disappointed many of the participants.

c. The company's profits declined rapidly (falling by almost 50%) in the last quarter.

d. Could you please bring me a glass of water (preferably cold) from the kitchen?

The correct answer is d. Could you please bring me a glass of water (preferably cold) from the kitchen?

Option d does not use parentheses correctly. Instead, it should use commas to separate the additional information. The corrected sentence would be:

Could you please bring me a glass of water, preferably cold, from the kitchen?

To determine which option uses parentheses correctly, we need to understand the purpose of parentheses. Parentheses are used to enclose additional information that is not essential to the main point or structure of the sentence.

Let's analyze each option:

a. Option a uses parentheses correctly. The phrase "(or at least it seemed that way)" adds additional information without changing the main point of the sentence.

b. Option b also uses parentheses correctly. The phrase "(due to the weather)" provides additional information about the reason for canceling the event.

c. Option c uses parentheses correctly as well. The phrase "(falling by almost 50%)" adds supplementary information about the decline in the company's profits.

d. Option d does not use parentheses correctly. The phrase "(preferably cold)" provides a preference but does not serve as non-essential information. A better alternative would be to use commas: "Could you please bring me a glass of water, preferably cold, from the kitchen?"

Therefore, the correct answer is d.