Concept:
To change an assertive sentence in the Simple Present tense into an interrogative sentence, we use the auxiliary verb "Do" or "Does" followed by the subject and the base form of the main verb.
Step 1: Identify the Tense and Subject.
The original sentence is "She enjoys reading books."
• Subject: She (Third-person singular)
• Main Verb: Enjoys (Simple Present)
Step 2: Applying the Auxiliary Verb rule.
For third-person singular subjects (He, She, It, or a singular noun), we must use "Does".
A crucial rule is that once "Does" is used, the main verb must return to its base form (without the 's').
• Correct: Does + she + enjoy
• Incorrect: Does + she + enjoys
Step 3: Evaluating the options.
• Option A: Uses "Is," which is for continuous tenses, not simple present.
• Option B: Uses "Do," which is only for I/You/We/They.
• Option C: Uses "Does" but keeps the 's' on "enjoys," which is a grammatical error.
• Option D: Correctly uses "Does" and the base form "enjoy."
Final Answer: Option D