Billy is nine years old. his mother allows him to walk to school on his own. what responsibility is billy’s mother displaying?
a) making an unpopular decision that billy will not approve
b)teaching her child independence
c)disciplining her child
d)not caring for her child enough

D. not caring for her child enough. A mother should always walk with her child when they're 9. 

A mother should care for her child no matter what. Even if they know that the child will hate them for it. 
It's good to teach them indepence, as you don't want them to always ask you for help for everything... but that'll be too early. 
I don't see how discipling make sense, you should never discipline by letting the child walk to school on their own, more like take something away or something that will not get them killed/injured. 

Hope I helped! 

Primary effectit is the most accurate.