$($a$)$ Compare $$Mn for singly reinforced rectangular beams having the following properties.

$($b$)$ Taking beam $1$ as the reference point, discuss the effects of changing As$,$ fy$,$ fc

$$

$,$ d$,$ and b on

$$Mn$.($Note that each beam has the same properties as beam $1$ except for the italicized

quantity.$)$

$($c$)$ What is the most effective way of increasing $$Mn$?$ What is the least effective way?