Explanation:

- Option 1: Parsons – Talcott Parsons was a key figure in functionalism but is not known for the manifest and latent functions distinction.

- Option 2: Durkheim – Émile Durkheim also contributed to functionalism, focusing on social facts, but did not propose this distinction.

- Option 3: Merton – Robert K. Merton made the distinction between manifest functions (intended and obvious) and latent functions (unintended and hidden) in social structures.

- Option 4: None – This option is incorrect, as the correct theorist is listed above.