Set up a definite integral that represents the indicated shaded area over the interval $[$a$,$b$].$

A$.{\displaystyle \underset{a}{\overset{\phantom{}}{}}}-[k(x)+g(x)]dx$

B$.{\displaystyle \underset{a}{\overset{\phantom{}}{}}}g(x)dx$

C$.{\displaystyle \underset{a}{\overset{b}{}}}[k(x)-g(x)]dx$

D$.{\displaystyle \underset{a}{\overset{b}{}}}[g(x)-k(x)]dx$

E$.{\displaystyle \underset{a}{\overset{b}{}}}k(x)dx$

F$.{\displaystyle \underset{a}{\overset{b}{}}}[k(x)+g(x)]dx$