Answer:
Option: C is the correct answer.
C. Tetrahedron.
Explanation:
Platonic solid--
Platonic solid is a convex polyhedron which is constructed with the help of repetition of regular convex polygonal faces.
There are 5 types of platonic solid:
1) Tetrahedron--
It is a polyhedron which is composed of four triangular faces.
2) Cube--
It is a polyhedron which is constructed with the help of square faces and has 6 faces.
3) Octahedron--
In geometry a octahedron is a polyhedron with 8 faces.
Each of the face is composed of equilateral triangles.
4) Dodecahedron--
It is a polyhedron which consist of 12 faces.
5) Icosahedron--
It is composed of 20 faces.
Hence, the only Platonic solid with less than five faces is :
C. Tetrahedron