A forest is in the shape of a rectangle 5 miles long and 3 miles wide. The density of the trees at a distance of x miles form the 5 mile side is given by p(x) trees per square mile. Which expression gives the number of trees in the forest?

Aintegral from 0-3 p(x) dx

B.3 Integral from 0-3 p(x) dx

c.5 Integral from 0-3 p(x) dx

D3 Integral from 0-3 p'(x) dx

E.5 Integral from 0-3 p'(x) dx