The expansion of the North American railroad and transportation system facilitated immigration in that:

A) The construction of railroad structures offered lucrative and profitable work to skilled tradespeople, drawing immigrants to jobs on rail lines
B) The transportation network made travel faster and cheaper, improving immigrant families’ access to unsettled homesteads
C) Mining companies in the West partnered with railroads to offer cheap passage for immigrants to take jobs in mines struggling to meet high demand for production
D) Railroads offered jobs to immigrant women to work as servants to wealthy travelers aboard passenger trains