The shape of a geometry box is:-
a) Rectangle
b) Circle
c) Square
d) Cuboid

Hint: Before solving this question, we must know the meanings of the following terms:-
a) RECTANGLE: A plane figure with four straight sides and four right angles, especially one with unequal adjacent sides, in contrast to a square.
b) CIRCLE: A round plane figure whose boundary consists of points equidistant from a fixed point that is its centre.
c) SQUARE: A square is a plane figure that is a regular quadrilateral, which means that it has four equal sides and four equal angles. It can also be defined as a rectangle in which two adjacent sides have equal length.
d) CUBOID:  A cuboid is a box-shaped object. It has six flat faces and all angles are right angles. Also, all of its faces are rectangles.

Complete step-by-step answer:
1. RECTANGLE: A geometry box can never be of a rectangular shape because, since a geometry box is not a plane shape, therefore it cannot be a rectangle. Though, all of its faces are of rectangle shape, i.e. all of its faces are rectangular.

2. CIRCLE: A geometry box can never be of a circular shape because, as mentioned above, a geometry box has rectangular faces. Therefore, the shape of a geometry box can never be of circular shape. Also, a circle is a plane shape while a geometry box is not of a plane shape.

3. SQUARE: A geometry box can never be of a square shape because square is a plane shape while a geometry box is not of a plane shape.

4. CUBOID: A geometry box is of a cuboid shape because a cuboid has similar appearance as that of a cuboid. A cuboid also has rectangular faces and a geometry box also has rectangular faces. A cuboid has 12 edges, 6 faces and 8 vertices. A geometry box also has the same number of faces, edges and vertices.

Therefore, the answer of this question is (d) Cuboid.

Note: One must always remember the properties of some basic 3 – dimensional shapes as they can come in handy.