<p>Critics pointed out that the new highway, which will run <span class="answer">through</span> the mountains, will cause irreversible damage to the environment and local wildlife.</p><div data-answer="d"><span style="font-size: 13.008px;">The correct answer is (D) through.
The word "through" is the correct preposition to use in this sentence to indicate the direction of the highway. It means that the highway will pass from one side of the mountains to the other. </span></div><div data-answer="d"><span style="font-size: 13.008px;"><br></span></div><div data-answer="d"><span style="font-size: 13.008px;">(A) "Thorough" is an adjective meaning complete or detailed, and it does not fit in the context of the sentence.</span></div><div data-answer="d"><span style="font-size: 13.008px;">(B) "Thought" is a noun meaning the process of thinking or considering something. It is not the correct word to describe the direction of the highway.</span></div><div data-answer="d"><span style="font-size: 13.008px;">(C) "Throughout" is a preposition meaning in every part of or during the whole time of something. It does not convey the direction of the highway running through the mountains.
Therefore, the correct answer is (D) through.</span><br></div>