Explanation:

people who enjoy social company

To find the correct one word substitution for thee given group of words we need to see the meaning of the words given as options.

1. gregarious -  fond of company; sociable.

2. gorgeous - beautiful; very attractive.

3. herbivorous -  feeding on plants.

4. unanimous -  fully in agreement.

Hence after looking at the meanings we can conclude that the correct substitution for the group of words is 'gregarious'

Hence option 1 is the correct answer.