Correct Answer: dubious

Solution : The correct choice is the second option.

Explanation:
The most suitable antonym for genuine is dubious.
Dubious means doubtful or uncertain, contrasting with genuine, which implies authenticity and truthfulness.
The meanings of the other options are as follows:

• Honest: Truthful and sincere.
• Authentic: Real, genuine, or true.
• Pure: Not mixed or adulterated; free from impurities.

Therefore, the correct answer is dubious.