3. A Safe Rider bicycle headgear set consists of the following: box, warranty, instructions for use, helmet, extra pads for sizing, and reflective decals. The headgear assembly consists of the helmet and chin strap. The helmet consists of an inner and outer shell.

The inner shell consists of a shell with padding on the side closest to the head. The chin strap consists of webbing and a snap assembly.

a. Draw a product structure tree for the Safe Rider bicycle headgear set.

b. Construct a single-level bill of materials for the kit and each of its components.