"A scholar must be ambitious, and the road ahead is long and arduous." is a sentence said by Zeng Zi in "The Analects of Confucius Taibo Chapter"

Original text "A scholar must be ambitious, and the road ahead is long and arduous. Isn't it important to be benevolent when one considers one's responsibilities? Isn't it too far to do it only after death?" It means that as a scholar and a gentleman, you must be broad-minded and tenacious. quality, because one has a heavy responsibility and a long way to go.

A sentence said by Zeng Zi in "The Analects Taibo Chapter"

So the answer is C. Zeng Zi