What is the name of the cylindrical milling cutter that has multiple cutting edges spiraling down its sides?

The correct choice is the cylindrical milling cutter that has multiple cutting edges spiraling down its sides, which is known as a slab mill. This type of cutter is designed to remove material across a wide area of a workpiece, making it highly effective for creating flat surfaces or large features.

Slab mills have a cylindrical shape and are equipped with teeth located around the circumference, which enables them to perform effective cutting as they rotate. The spiral design allows for a continuous cutting action along the length of the cutter, providing smooth surface finishes and efficient material removal. This characteristic distinguishes slab mills from other types of milling cutters, such as end mills or face mills, which serve different milling purposes.