Question

So though several times messengers were started out to carry our letters to the coast, they were turned back by the Boxers before they had gone far. It was not long before the Boxers, like a pestilence [contagious disease], had spread all over Shansi. School had not closed yet in Fen Chou Fu, but as the feeling of alarm deepened, fathers came to take their boys home, and school was dismissed before the end of June.

—The Boxer Rebellion,
Fei Ch'i-hao, 1900

Why did fathers take their boys out of Christian school early?

so the boys could work in the fields
to protect the boys from the Boxers
so the boys could join the Boxers
because the fathers could not send letters

Answer 1

Fathers took their boys out of Christian school early in order to;

B. To protect the boys from the Boxers

The Boxer Rebellion that emerged in China opposed foraneous influence in religion, politics, commerce, and technology.

During this time, The Boxers proceeded to murder Christians. When the fathers were alarmed of this, they took the action of taking their kids out of school to protect them from The Boxers.