Mark is at an age where his eyes light up with wonder at the sight of large moving objects, whether it's a massive truck rumbling by or a powerful train chugging along the tracks. He finds joy in getting his hands dirty, digging in the earth, and experimenting with various textures and materials. The truck would be the perfect Christmas gift for him, sparking his imagination and continuing his fascination with hefty machines while allowing him to enjoy creating and playing in the dirt. This toy would provide endless opportunities for exploration and hands-on fun, perfectly aligning with his interests.