The Railway Train By Emily Dickinson

I like to see it lap the miles,
And lick the valleys up,
And stop to feed itself at tanks;
And then, prodigious, step
Around a pile of mountains,
And, supercilious, peer
In shanties by the sides of roads;
And then a quarry pare
To fit its sides, and crawl between,
Complaining all the while
In horrid, hooting stanza;
Then chase itself down hill
And neigh like Boanerges,
Then, punctual as a star,
Stop- docile and omnipotent
At its own stable door.

Which line of the poem makes it clear that the train is being compared to a horse?

A. "In shanties by the sides of roads"
B. "And then the quarry pare"
C. "Complaining all the while"
D. "And neigh like Boanerges"​