Truncated octahedral (cube-octahedra) is called ‘case’ or ‘sodalite cage’.
a.) True
b.) False

Hint: Truncated octahedral is structure formed from four and six tetrahedral structures. It is a ring structure composed of fusion of these four or six tetrahedral structures.

Complete step by step answer:
For this statement, first we will see what is a case or sodalite cage structure.
Sodalite is a cubic mineral. It forms a structure in which Na cations are in the interframework of aluminosilicate cage networks. The unit cell formed each consists of two cage structures.
The truncated octahedron is formed by fusion of rings of four and six tetrahedral. The linking in truncated octahedron form zeolite which has ‘case’ or ‘sodalite cage’ structure.
We can see that it looks somewhat like this.


Thus, the statement given to us is true.

Additional Information:
This octahedron is an Archimedean solid. The structure is composed of 12 square faces, 8 regular hexagonal faces, 6 regular octagonal faces, 48 vertices and 72 edges.
This is even called a zonohedron because each face of the octahedron has point symmetry.
As it has foam-like tessellatory efficiency and permutohedral nature; thus, it can also be considered a three dimensional analogue of the hexagon.
We can even construct a truncated octahedron. It is done from a regular octahedron with side length 3a by the removal of six right square pyramids, each one from each point.

Note: Sodalite consists of chloride anions in the inter framework cages normally but in some structures, many other anions like hydroxide, sulphide etc. can also be seen. It is even known as an important container of many anions like iodide, iodate, perchlorate and permanganate etc.