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

A sentimental longing for a period in the past

Nostalgia

The word that can be used as a one-word substitute for "a sentimental longing for a period in the past" is nostalgia.

• Emotion is a strong feeling, such as happiness, sadness, or anger.
• Craving is a strong desire for something.
• Memory is a recollection of something that has happened.
• Nostalgia is a sentimental longing for a period in the past.

Nostalgia is the most appropriate word for the given group of words because it specifically refers to a sentimental longing for a period in the past. It is derived from the Greek words nostos, meaning "homecoming," and algos, meaning "pain."