Well C. would make an equilateral triangle, due to all three sides being the same. It could also be an isosceles triangle, due to both sides being the same.
Experiental probability is the correct choice because you will have actual data from an experiment that you are using to create the ratio of outcomes to attempts. This is the scientific and mathematical name for a tested ratio. Theoretical probability, on the other hand, is what you would expect to happen if you were to perform the test.
