Correct Answer: Ambivert

Solution : The correct choice is the second option.

Explanation: An ambivert is a person who has characteristics of both extroversion and introversion. They may display traits of being both open and outgoing in certain situations (like extroverts) and reserved or shy in others (like introverts).

Therefore, the correct one-word substitute would be, ambivert.

The meanings of the other options are as follows:

1. Extrovert : This term refers to a person who is outgoing, sociable, and enjoys being around people.
2. Introvert : This term refers to a person who is more reserved and enjoys solitude.
3. Controvert : This term does not exist, and it is not a recognised word.