The answer for the question shown above is the option C, which is: C- Regular square pyramid.
The explanation is shown below:
By definition a regular square pyramid must be a pyramid with a square base, which means that the sides of its base have the same length.
You can identify it as a pyramid because it has an apex, a height, lateral faces that are congruent isosceles triangles and slant height (the altitute of the lateral faces).
