Explanation:

- Trepidation is a noun that refers to a state of fear or anxiety about something that may happen.

- Option 1: Lucid means clear or easy to understand. It doesn't relate to fear or anxiety.

- Option 2: Fragrant describes a pleasant and sweet smell. This is unrelated to the feeling of fear.

- Option 3: Optional refers to something that is not mandatory or is a personal choice. It doesn't match the sense of fear or anxiety.

- Option 4: Excited state of mind can imply nervousness or anxiety. Thus, it closely resembles trepidation.

Option 4: Excited state of mind is the correct answer.