The max capacitance C$=50$pF and doping concentration is

$3$x$1017$cm$-3.$

$($a$)$ Is the substrate doping N type or P type?

$($b$)$ What is the thickness of the oxide in the MOS capacitor?

$($c$)$ What is the doping concentration of the substrate, Nsub?

$($d$)$ What is the value of the capacitance at position C on the C$-$V curve?

$($e$)$ At location B$,$ what is the band bending, $$s