I'll give you a question, please answer with step-by-step reasoning process.
Where would you find a metal rod in most people's preferred method of transportation?\nOptions:\n- airplane\n- construction site\n- shops\n- engine\n- broken bone

engine
Engine is one of the most prefferd mode of transportation.

Engines have rods in them as they are heavily made of metals.

.

The final answer: engine