The correct answer is: C. weak
A dauntless person is fearless and determined. They are not easily discouraged or intimidated. A weak person, on the other hand, is lacking in courage or strength. They may be easily discouraged or intimidated.
The other options are not antonyms of dauntless.
A cautious person is careful and prudent. They take steps to avoid danger or harm. A thoughtful person is considerate and reflective. They take the time to think about their actions and their impact on others. An adventurous person is willing to take risks and try new things.
In conclusion, the correct answer to the question “What is the antonym of dauntless?” is C. weak.