Which sentence contains the error of restating an explicit prohibition as mere absence of necessity?
The tasting session is optional, so visitors don't have to sample the new blend.
The service tunnel is restricted, so passengers mustn't open its gate.
The audio guide is optional, so families don't have to hire one.
The laser rule says looking into the beam is forbidden, but the summary says you don't have to look into it.✓Bonne réponse
Explication
The laser rule explicitly forbids looking into the beam, but don't have to look merely says that looking is unnecessary and therefore fails to restate the ban. The other sentences correctly pair optional actions with don't have to or a restricted action with mustn't.