Select the option that can be used as a one-word substitute for the given group of words.

A person preoccupied with an unrealistically optimistic approach to life

Quixotic

The one-word substitute for "a person preoccupied with an unrealistically optimistic approach to life" is quixotic.

• Pragmatic means concerned with practical matters and effectiveness rather than with theory or ideals.
• Practical means concerned with the actual doing or use of something rather than with theory or speculation.
• Rational means based on or in accordance with reason or logic.

Quixotic means having or showing an idealistic but unrealistic and impractical set of aims or principles. It is the most appropriate word for the given group of words because it specifically refers to an unrealistic optimism.