#7

[JenniferK632]

Thanks in advance!

[Misti Duvall]

Happy to help, but first can you please clarify your question?

[WilliamS670]

Thanks in advance!

(B) and (A) are the contenders. (B) is correct, because there's a layer of permeable rock, at the appropriate depth, to allow for injection, above which there's a layer of impermeable rock that protects against contamination of drinking water.