Nearly all enzymes that require a nicotinamide cofactor use either NAD ${?}^{**}/$ NADH or NADP ${?}^{**}/$ NADPH but not both. Compare the net charge of each cofactor.

the net charges are $NA{D}^{}-2,$NADH$-2,NAD{P}^{}-3,$ and NADPH$-3.$

the net charges are $NA{D}^{}1,NAD{H}^{}-2,NAD{P}^{}2,$ and NADPH$-3.$

the net charges are $NA{D}^{}-1,$NADH$-2,NAD{P}^{}-2,$ and NADPH$-3.$

the het charges are $NA{D}^{}1,$NADH$-1,NAD{P}^{}1,$ and NADPH$-1.$