Explanation:

- The group of words describes someone who is overly optimistic about life in a way that may not be grounded in reality.

- Quixotic:

- Refers to someone idealistically unrealistic and impractical, similar to Don Quixote's character known for hopelessly romantic and impractical pursuits.

- Correct Answer.

- Pragmatic:

- Describes someone who is practical and deals with things sensibly and realistically.

- Practical:

- Indicates someone focused on what is effective and realistic in actual situations.

- Rational:

- Describes someone based on or agreeable to reason and logic.