Which indicator would suggest that a conclusion is a direct effect of an action?

The phrase "leads to" is a key indicator that suggests a direct causal relationship between an action and a conclusion. When one event leads to another, it implies that the first event has a direct influence on the occurrence of the second event. This causal sense helps establish a clear link where the action is the catalyst for the result or conclusion.

For example, if a statement claims that a specific action "leads to" a particular outcome, it explicitly communicates that the outcome is a consequence of the action taken. This framing is essential in logical reasoning as it helps to identify how conclusions can be drawn based on the relationships between different statements or events.

In contrast, the other choices imply different relationships. "Must" indicates a necessity or obligation rather than a causal link, "when" refers to a timing aspect without establishing causation, and "unless" introduces a condition that negates the action without confirming its effect. Thus, "leads to" is the most straightforward indicator of a direct effect in this context.