Which part of speech is the underlined word?

at dusk, they walked quietly along the railroad tracks.

a.
adjective

b.
adverb

c.
verb

d.
noun
railroad is underlined

Which historical events have affected the meals you consume? check all that apply. columbus brought sugar cane to the new world in the late 15th century. italian immigrants brought pizza to the united states in the early 1900s. tacos were first eaten in the silver mines of mexico during the 1700s. sugar cane spread throughout the muslim world, and methods were developed to refine it. immigrants introduced chinese food to san francisco in the mid-1800s. people from the middle east created the modern version of roasting coffee in the 13th century.