Explanation:

Let’s break it down:

- Option 1: Social Facts

Durkheim does talk about social facts in his work, but he's more focused on defining what they are and how to study them using a sociological perspective—not necessarily using the indirect experiment method here.

- Option 2: Religion

In “The Elementary Forms of Religious Life,” Durkheim looks at religion sociologically, but his method is comparative and analytical, not primarily indirect experiment.

- Option 3: Suicide

This is where the indirect experiment method comes in. Durkheim couldn’t set up experiments about suicide rates, so he compared different social groups, regions, and times to indirectly understand the social causes. He’s famous for using this approach in his study on suicide.

- Option 4: Division of Labour

Here, Durkheim is dealing more with theory and historical analysis, talking about how societies change—not really the indirect experimental approach.

So, the right answer is Option 3: Suicide. That’s the work where Durkheim really applies the indirect experiment method to uncover connections between social structure and suicide rates.