the question states that they are similar, so B is automatically an option. It's 8 times because the radius and height are being doubled. Logically there are more factors to be A and E.
2.96 meters per second is the answer I'm getting. I took the total seconds and divided it by how many times he ran around the track to get his speed for lap and then I divided his lap speed by how long the track was to get his meters per second