What effect did the standard gauge have on railroad lines? a. It allowed an engineer to stop all cars on a train at once. b. It allowed railroads to form a cross-country network. c. It converted some

What effect did the standard gauge have on railroad lines?

a.

It allowed an engineer to stop all cars on a train at once.

b.

It allowed railroads to form a cross-country network.

c.

It converted some railroad cars into “hotel rooms on wheels.”

d.

It allowed railroads to carry freight as well as passengers.