During the 1800s an important pull factor for immigrants to the united states was

Many immigrants wanted to start a new life and settle but this was also with the free land many wanted to become farmers. The railroad construction also called for many workers.

Pull factors were religious freedom, job opportunities and political liberty. Immigrants wanted to leave their country because they wanted to escape from religious persecution, increase in population, and wanting to become rich because of the California Gold Rush. Hope this helped please rate as brainlest thank!! :)

I’m pretty sure that the answer is b.