Teresa knows that the apparent magnitude of a star is a measure of the brightness of the star as it appears to the observers on Earth. The apparent magnitude Mof the dimmest star that can be seen with a telescope is given by the function: M=5log D+2 where D is the diameter (in millimeters) of the telescope's objective lens. If Teresa’s telescope can reveal stars with a magnitude of 12, what is the diameter of its objective lens?