Answer:
The correct answer is "How could you have the heart to put your own child out among strangers ?"
Step-by-step explanation:
That phrase is the one that best supports the theme that society can put mothers in impossible situations, even something as extreme as leaving their own children among strangers.
The phrase says "How could you have the heart" establishing that this mother, as well as the other mothers in society are judged and labeled heartless for doing things like this.
When the situation becomes impossible, and a mother has to move forward even for the well-being of her child, she must do "disheartened" things because it is the only alternative she has. If society did not make this so impossible, perhaps the ways of acting would be different.