Regarding the cantilever beam shown below $($constant El beam$),$ select the best answer:

${}_{\text{M}\text{A}\text{x}}=$

$$

a$.$ The area under the moment function

b$.$ The area under the M$/$El function

c$.$ The are under the moment function plus a constant of integration: $C_1$

d$.$ The area under the $\frac{M}{E}l$ function plus a constant of integration: $\frac{C_1}{E}I$

e$.$ None of the above are accurate