Final answer:
The optimum angle for the maximum range of a projectile is A) 45 degrees, but if air resistance is considered, the maximum angle is approximately 38 degrees. For every initial angle except 45 degrees, there are two angles that give the same range.
Step-by-step explanation:
The optimum angle at which a projectile should be launched in order to cover the maximum distance is 45 degrees. This is true for conditions neglecting air resistance. However, if air resistance is considered, the maximum angle is somewhat smaller, approximately 38 degrees. It is interesting to note that for every initial angle except 45 degrees, there are two angles that give the same range, and the sum of those angles is always 90 degrees.