Correct Answer:
C. is
Explanation:
The correct answer is is because the true grammatical subject of the sentence is the singular pronoun 'One', not the plural noun 'books'.
- Step 1 (Subject Identification): In 'one of the books', the subject is 'One', not 'books'.
- Step 2 (Verb Agreement): 'One' is singular, so it takes the singular verb 'is'.
- Incorrect Options:
- are is plural and incorrect.
- were is past plural and incorrect.
- have is not suitable as a linking verb here.