The answer is A Chronologically because I just took the test and the answer was right..!!!!!! Make my the brainiest PLEASEEEEE!!!!!!!
The correct answers are A and B. They refer to setting up a home, that is becoming mature so as to create your own home. The other choices simply do not reflect an idea of becoming independent or maturing in any other way.
I personally would write it as:
"I doubt they'd send their kids to school if it wasn't safe."
Hope this helps!