Explanation:

- Max Weber is well-known for his "micro" approach in sociology. He focused on individual actions, meaning, and social interaction—hallmarks of micro-sociology.

- Karl Marx mainly analyzed large-scale structures, like class and capitalism, which are "macro" aspects.

- Émile Durkheim also took a macro approach, emphasizing social facts, institutions, and collective behavior over individual actions.

- Therefore, among the given options, only Weber studied the micro aspect.

Option 1: Marx and Weber

Incorrect. Marx did not focus on the micro aspect.

Option 2: Marx and Durkheim

Incorrect. Neither focused on micro aspects.

Option 3: Weber only

Correct. Only Weber took a micro-level approach.

Option 4: Durkheim only

Incorrect. Durkheim studied macro aspects.