$($a$)$ In beam shear design, we only need the values at the critical sections, from the shearing force diagram but never the corresponding values from the normal force and bending moment diagrams. Is this a correct statement? justify your answer using a neat sketch.

$($b$)$ According to the CSA A$23\mathrm{.}3,$ reinforced concrete sections under flexure are designed to crack. Is this a correct statement for any cross section? justify your answer using a neat sketch.

$($c$)$ As a designer, if you need to increase a cross section capacity in flexure, you would either increase $d$ or $A_s$ as both essentially have the same effect. Is this a correct statement? justify your answer.