Correct answer: C. Engine revolutions.
The rev counter measures the speed of the engine, in revolutions per minute. Generally, the higher the revs, the more fuel the engine is using, so drivers should keep an eye on the rev counter to help drive in a more eco-friendly manner.
This is an official-style question from the Safe and Responsible Driving topic of the Ireland driver theory test (Cat. B). Practise all 807 questions free on iTest.ie — with timed mock exams, automatic mistake tracking and progress sync across devices.
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