Which components are part of a mortar round?

In the context of mortar rounds, the correct components include a fuse, body, and tailfins. The fuse is vital for initiating the explosive charge at the desired time during flight, ensuring the mortar round detonates upon reaching its target. The body of the mortar round houses the explosive material and is designed to withstand the forces during launch and impact. Tailfins are crucial for providing stability and maintaining the projectile’s trajectory during flight, helping to improve accuracy.

The remaining options include components that do not accurately reflect the standard elements found in a mortar round. For instance, while a detonator is part of the ignition system, it is typically categorized under the fuse. Additionally, a casing is generally associated with container or protection, not the primary components of a mortar round. Features like propulsion relate to the launching mechanism but are not direct components of the mortar round itself. Thus, the combination of fuse, body, and tailfins offers a complete and accurate depiction of what constitutes a mortar round.