About this 3D model

Tippy Tipmas everyone! Bring some holiday cheer to your Tippi Tree with this decorative puzzle. Can you figure out how to stick every present under the Tippi Tree? Pieces must be stuck directly to the roots and restricted from moving in any direction but up. Parts are labeled in groups A, B, C, and D. In my example, Group A is Yellow, B is Red, C is Silver, and D is Gold. For the solution click here: SPOILER