Select the most appropriate one word substitution for the given group of words.

A person very reserved in speech

Reticent

he most appropriate one word substitution for the given group of words "a person very reserved in speech" is reticent.

• Confident means feeling or showing confidence in oneself or one's abilities or qualities.
• Reticent means not revealing one's thoughts or feelings readily.
• Adamant means refusing to be persuaded or to change one's mind.
• Eloquent means fluent or persuasive in speaking or writing.

The word reticent is the most appropriate because it specifically refers to someone who is not talkative or open about their thoughts and feelings. The other words do not have the same connotation of speech suppression.