A projector shows an image which is in focus but too large for the screen on which it is shown. Since the projector and the screen are fixed in place, the projectionist must,
(a) adjust the projector's lens by moving it closer to the screen.
(b) adjust the projector's lens by moving it farther from the screen.
(c) replace the projector's lens with one having a shorter focal length.
(d) replace the projector's lens with one having a longer focal length.