Correct Answer: passionate

Solution : The right choice is the fourth option .

In the context of the sentence, "ardent" describes Simon as a devoted and enthusiastic follower. "Passionate" is a synonym that captures this sense of intense dedication and fervour. Simon's being an "ardent follower" suggests that he is deeply committed and passionate about whatever he is following.

The meanings of other words are as follows:

• Adverse means harmful or unfavourable.
• Objective refers to being unbiased or not influenced by personal feelings or opinions when considering and representing facts.
• Casual implies a relaxed or unconcerned attitude; something not serious, planned, or thorough.

Therefore, the correct answer is passionate.