From the image, we are asked the number of sides a polygon can have to form a regular tesselation.
The first step is to understand what a regular tessellation is;
A regular tessellation is a highly symmetric, edge-to-edge tiling made up of regular polygons, all of the same shape. There are only three regular tessellations: those made up of equilateral triangles, squares, or regular hexagons.
This implies that it could either have 3 sides(triangle), four sides(square), six sides(hexagon).
From the given options we can clearly see that 3 sides is the only available option.
ANSWER: Option B