Final answer:
The Full choke has the tightest shot pattern, designed for long-range shooting, as opposed to Cylinder, Improved Cylinder, and Modified chokes that offer progressively wider spreads for closer ranges.
Step-by-step explanation:
The shotgun choke that has the tightest shot pattern is the Full choke. The primary purpose of a choke is to shape the spread of the shot in order to gain better range and accuracy.
A Full choke is very constrictive and therefore results in a narrow and compact spread, making it suitable for distant targets where you need a concentrated shot pattern. Comparatively, the other chokes mentioned, such as the Cylinder, Improved Cylinder, and Modified, offer progressively less constriction, meaning that the shot pattern will spread out more quickly.
The Cylinder choke provides the widest spread suitable for close-range shooting, the Improved Cylinder choke allows slightly more constriction, the Modified choke offers a moderate constriction useful for mid-range shooting, and the Full choke has the tightest constriction for long-range accuracy.