Final answer:
The sentence uses figurative language to describe the increasing popularity of dressing up for Halloween each year.
Step-by-step explanation:
The correct answer is a. figurative language. Dressing up for Halloween becoming more popular each year is an example of figurative language because it uses exaggeration to emphasize the increasing popularity of Halloween costumes. It is not meant to be taken literally, as the act of dressing up does not actually multiply each year.
Learn more about Figurative language in a sentence about Halloween costumes