Which term describes the area of bedrock from
which soil forms?
a) a horizon
b) b horizon
c) parent rock
d) mineral deposit

b horizon

i think that is right

explanation:

when a reversible reaction is occurring in both directions at the same rate; the products and reactants do not change in concentration. a chemical reaction where the compound is broken into its constituent parts.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".