Explanation:

- Solitude refers to the state of being alone, often by choice, and usually without feeling lonely. It can be seen as a peaceful or reflective state.

- Option 1: Retirement implies pulling away from active life or work but does not directly oppose solitude.

- Option 2: Concealment refers to hiding something, which is unrelated to solitude.

- Option 3: Tease means to make fun of or provoke. It's not a direct opposite of solitude, as it doesn't refer to social interaction in itself.

- Option 4: Conducive means making a situation likely or possible. It's not related as an antonym to solitude.

The nearest antonym for solitude would involve social interaction or presence of others, which none of these options directly imply.

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