In politics, one must be careful not to cross the line.What does the underlined idiom mean?

Explanation

The correct answer is Option A: To break a rule or limit. The idiom 'cross the line' is commonly used to indicate that someone has acted inappropriately or has exceeded acceptable behavior, especially in sensitive areas like politics. Option B, 'to travel far,' is unrelated as it discusses distance rather than behavior. Option C, 'to lose hope,' refers to emotional states and does not connect to the idea of limits or rules. Finally, Option D, 'to make a mistake in math,' is entirely off-topic and does not pertain to the idiom's meaning.