Yes - they have to be similar. Since they are using the same line as the hypotenuse, the ratio of the other two sides are in the same ratio (ie, the slope of the line), the 3 inner angles will be the same. Thus, the triangles will be similar.
B because it's not putting the blame on anyone. It is completely unbiased and objective.
Forgive if I am wrong, but I think the answer is 360 feet cubed