Question

Here is a question :D
The chemical composition of soil depends largely on the

topography
parent rock
soil's A horizon
soil's B horizon

Answer 1

https://books.google.com/books?id=EvTwAAAAMAAJ&pg=PA119&lpg=PA119&dq=The+chemical+composition+of+soil+depends+largely+on+the+topography+parent+rock+soil%27s+A+horizon+soil%27s+B+horizon&source=bl&ots=mO2KFTE8sb&sig=tWRnjI_K688-6diUs1yQ__8D4-c&hl=en&sa=X&ei=SuavVJDCMIWWNrGDhLAG&ved=0CDQQ6AEwAw#v=onepage&q=The%20chemical%20composition%20of%20soil%20depends%20largely%20on%20the%20topography%20parent%20rock%20soil's%20A%20horizon%20soil's%20B%20horizon&f=false

This site, (I know, the link is ridiculously long) says A. topography and B parent rock.