A bus is operated by a driver (thing → operator). By the same relation, a machine is operated by whom?

Introduction / Context:
Using Recovery-First, “Diver” is corrected to “Driver” to restore the operator relation: bus → driver. We now need a comparable pair: thing/equipment → person who operates it. “Machine : operator” is the exact parallel.

Given Data / Assumptions:
Maintain the operated-by link.

Concept / Approach:
We prefer pairs where the second term is the canonical role that runs the first. Kitchens are places, students attend classes, soldiers fight wars; these are not precise “operator of device” mappings. “Tool : mechanic” flips the relation: the mechanic operates tools, but the structure is reversed relative to the stem. “Machine : operator” matches directly.

Step-by-Step Solution:

Verification / Alternative check:
Operator is the standard role label across machinery domains.

Why Other Options Are Wrong:
They do not preserve the “operated-by” relation.

Common Pitfalls:
Confusing participants with operators, or reversing the direction.

Final Answer:
Machine : Operator