Answer: The best way to correct sentence 2 is option C:
"These blood vessels are very fragile and lie very close to the surface, which makes them easy targets for injury."
Explanation:
Option C corrects the subject-verb agreement by using the plural verb "lie" to agree with the plural subject "blood vessels." The sentence also uses the correct adjective "very" to modify "fragile" and the singular verb "makes" to agree with the singular noun "which." The sentence is grammatically correct and conveys the intended meaning clearly.