Question

alice: do you know, ive always wanted to meet a burglar. but its so difficult. they go out so seldom.
hatch: yes, and they arrive so late.
alice: (laughingly) now, thats much better. its so nice of you to have a sense of humor.
(three locomotive whistles are heard from just outside the house.)
alice: ah! at last! theyve come. theyve come!
hatch: (fiercely) theyve come! what is it? what does that mean?
(reddy runs to window and opens the shutters.)
alice: (jubilantly) it means - it means that twenty men are crossing that lawn. it means that while you sat drinking there, civilization was racing toward you at seventy miles an hour!
(sha drags open the curtains, disclosing captain lucas and two other policemen.)
captain lucas: hold up your hands, all of you!
alice: (speaking with an effort and swaying slightly) hush, please. dont - dont alarm my mother. mothers not as strong as - as i am.
the passage, what is the significance of the three locomotive whistles?
they signal the arrival of help.
they indicate the burglars escape.
they are a signal between burglars.
they are part of alices imagination.

Explanation:

In the passage, Alice is excited about the locomotives' whistles as help (like the arrival of the police/Captain Lucas and others to deal with the burglars situation). The first option's "help" aligns with the context of the arrival of those who can assist (since there's a burglary situation and the whistles precede the arrival of Captain Lucas and others). The other options: they aren't a signal between burglars (no indication of that), don't indicate burglars' escape (they come to address the burglary), and aren't part of Alice's imagination (the arrival is real with Captain Lucas and policemen).

Answer:

A. They signal the arrival of help