Supply should constantly strive to standardize

a$.$ capital equipment purchases, raw material purchases, maintenance, repair, and operations $($MRO$)$ supplies purchases, and services purchases and supply management processes

b$.$ supply management processes

c$.$ raw materials purchases and supply management processes

d$.$ raw materials purchases

e$.$ capital equipment purchases, raw material purchases, maintenance, repair, and operations $($MRO$)$ supplies purchases, and services purchases