Answer:
C) Regular Octagon.
Explanation:
First let's see what a tessellation is.
Tessellation is a floor made by regular types of tiles without overlapping and gap.
We cannot use all shape of tiles to tessellate a plane.
We are given Regular pentagon, irregular triangle and regular octagon.
The pentagon has 5 sides, all sides are in the same length. We cannot tessellate a plane using pentagon.
The second figure is a irregular triangle, we cannot make tessellate a plane using irregular shapes.
The third figure is a regular octagon. We can tessellate a plane using a regular octagon.
Therefore, answer is C) Regular Octagon.