What did Thornton claim Buck could do? Did Buck do this?

John Thornton claimed that Buck would risk his own life on John Thornton's demand. He demonstrated this when John signaled to Buck to jump into the river. By doing so, Buck risked his own life.

hope this helps

Explanation:

try rewatching the movie a couple times and taking notes in between it will i promise, this may not be the answer you were looking for but it is just a suggestion, good luck with your project boo < 33

op: object of preposition