The production steps for pellets in order are:

a$.$ Extrusion$---$Dry mixing$---$wet massing$---$drying$---$spheronization

b$.$ Dry mixing$---$wet massing$---$Extrusion$---$spheronization$---$drying

c$.$ Dry mixing$---$Extrusion$---$spheronization$---$wet massing$---$drying

d$.$ Dry mixing$---$wet massing$---$spheronization$---$extrusion$---$drying

Clear my choice