What does the exposure compensation function of a digital slr camera do? a it allows the user to make adjustments before pressing the shutter to make the resulting photo lighter or darker. b it allows the user to choose the aperture, while the shutter speed is set by the camera. c it allows the user to choose the shutter speed, while the aperture is set by the camera. d it allows the user to keep the shutter opened manually, allowing for a long exposure.