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

Animals living in flocks

gregarious

The most appropriate option which is the one-word substitution for the given group of words "animals living in flocks" is gregarious.

• Social means enjoying the company of others.
• Gregarious means tending to form groups or herds.
• Bohemian means unconventional in lifestyle or behavior.
• Herbivorous means eating only plants.

The word gregarious is the most appropriate because it specifically refers to animals that live in groups or flocks. The other words do not have the same connotation of being animals that prefer to be around others.