Answer:
He advises Arthur to make a treaty with Sir Mordred for a month instead, as Sir Lancelot will come back during that month and kill Sir Mordred for him.
Explanation:
It could be ex peculated that after confronting the teacher, Marcus would back down because he might feel threaten. The teacher asked him if he knew that "Zero - tolerance mean" and that could be taken as a tense situation, he might have to options. To apologise to him or face the consequences within this "zero tolerance" atmosphere. <span />