Question

Who is thought to have studied with the grandson of confucius?

Answer 1

Mencius is thought to have studied with the grandson of Confucius.

Answer 2

I believe the correct answer is Mencius.
Mencius was also a famous Chinese philosopher, like Confucius. He is actually considered to be the second Sage, the first one being Confucius himself. He is a follower of Confucianism, which was imparted on him by Confucius's grandson, Zisi, among other people.