Several scientists are working in a laboratory. The scientists are experimenting with sources which emit ionising radiation. Each scientist is given a list of safety rules. Three of the rules are shown.
Keep at least 2 m away from other people.
Do not stay longer than 4 hours per day in the laboratory.
Stay behind the lead-lined screen.
Which safety rules are for protection against the effects of ionising radiation?
I and II only
I and III only
II and III only
I, II and III
