Final answer:
The component 'Choke' is not part of a cartridge or shotgun shell; it is a constriction in the shotgun barrel that affects the shot spread. A wad, bullet, and slug are all parts of ammunition.
Step-by-step explanation:
The component that is not a part of a cartridge or a shotgun shell is b) Choke. A shotgun shell or cartridge typically consists of the following parts: a) Wad, which separates the shot and the powder and also serves to compress the powder and seal the gas; c) Bullet, which is the projectile in a rifle or handgun cartridge; and d) Slug, which is a single large projectile in a shotgun shell designed to be fired from a shotgun. The Choke is actually part of the shotgun itself, not the ammunition. It is a constriction at the muzzle end of the barrel that shapes the spread of the shot to enhance range and accuracy.