Correct answer: A. It can seriously reduce visibility.
It is essential that all vehicle windows are clear and clean at all times so that drivers can see road and traffic conditions all around. Dirty windows are a particular hazard when the sun is low in the sky. Dirty windows also decrease visibility during hours of twilight and darkness.
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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