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?