Answer: C) Farmer : tractor.
Explanation: an analogy is a comparison between one thing and another, usually with the purpose of explanation or clarification, this comparison is based on one similarity or difference between specific features of two things. The relationship between the words "firefighter" and "fire truck" is that firefighters drive fire trucks (while they are working). From the given options, the pair of words that has the same relationship, is the corresponding to option C: "farmer" and "tractor" because farmers drive tractors (while they are working).