Choose the word that can substitute the given group of words.

One who looks at the dark side of life

Pessimist

The word that can substitute the given group of words is pessimist.

• Extrovert means someone who is outgoing and enjoys being around people.
• Pessimist means someone who tends to see the negative side of things.
• Libertine means someone who is free-spirited and unconventional.
• Anarchist means someone who believes in the absence of government.

Pessimist is the most appropriate word for the given group of words because it specifically refers to someone who tends to see the negative side of things. It is derived from the Latin word pessimus, meaning "worst."