Correct answer: A. They have no effect.
The hazard lights work independently of the other lights on the vehicle (except the direction indicators), and have no effect on the brake lights. Use the hazard warning lights to warn other road users of a danger ahead, when your vehicle is broken down and causing an obstruction, or when you needs to slow down sharply on a motorway.
This is an official-style question from the Managing Risk 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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