Volume of a cylinder = πr²h. Substitute r=9 and h=67: volume = 3.14 × 9 × 9 × 67 = 17040.78 cubic mm. Think of a cylinder as many equal circular layers stacked up. So we find the circular base area πr² and multiply by the height. The answer is in cubic units, so the correct choice is 17040.78 mm³.