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

One who takes a dark view of things

Pessimist

The word that can be used as a one-word substitute for "one who takes a dark view of things" is pessimist.

• Pedant is a person who is excessively concerned with minor details and rules.
• Periscope is an instrument for viewing objects that are above or below the horizon.
• Polyglot is a person who speaks many languages.
• Pessimist is a person who tends to see the worst in things and expects bad things to happen.

Pessimist is the most appropriate word for the given group of words because it specifically refers to a person who has a negative outlook on life. It is derived from the Latin word pessimus, meaning "worst."