Can someone me with this geometry question 100% correct only

Triangular Prism is incorrect because that moreover looks like a rectangular base with the sides of triangles. It's close but not quite.  The square prism is the same thing, but except for triangles, they have a square like side and a rectangular base. A triangular pyramid has a base and sides or triangles. A square pyramid would most likely be the answer because it's sides consists of triangles whilst the square as it's base.