Explanation:

- Option 1: B.F. Hoselitz

- B.F. Hoselitz was an economist who also contributed to urban studies.

- He discussed the role of cities in economic development but did not specifically focus on classifying them as generative or parasitic.

- Option 2: Henri Prenne

- There seems to be a misspelling or misunderstanding in this name, as it doesn't correspond to a well-known figure in urban studies or classification of cities.

- Option 3: Milton Singer

- Milton Singer was an anthropologist who worked on cultural aspects of economic development.

- His focus wasn’t primarily on classifying cities as generative or parasitic.

- Option 4: Philip M. Hauser

- Philip M. Hauser was a renowned sociologist and urban studies scholar.

- He is known for contributions to urban sociology, but not specifically this classification.

Correct Answer: Option 1, B.F. Hoselitz