The sentence using a hyphenated adjective correctly is "After a long and challenging year, Asia was looking forward to a much-needed vacation to the mountains."
We can define an adjective as a word used to modify a noun. Adjectives basically give nouns qualities, for example:
When we combine two different words to form only one adjective and modify the same noun, we should use a hyphen. Take a look below:
We will only need the hyphen if the noun appears right after the adjective. That is why we can eliminate options B, C, and D. Option B can also be eliminated for another reason. We do not need a hyphen when one of the words forming the adjective is an adverb ending in -ly.
We are left with option A. It is correct to use a hyphen to form "much-needed" to modify the noun "vacation."
Learn more about adjectives here:
https://brainly.com/question/6651127
#SPJ1