What controls the amount of light entering the camera lens and reaching the charge coupled device?

The correct choice is focused on the f-stop, which is part of the aperture setting in photography. The f-stop determines the size of the lens opening, or aperture, which controls how much light is allowed to enter the camera. A lower f-stop number indicates a larger aperture that permits more light, while a higher f-stop number means a smaller aperture that allows less light to enter. This control over light is vital for proper exposure and achieving desired artistic effects in photography.

Conversely, shutter speed measures how long the camera's shutter remains open, impacting exposure duration rather than light entrance through the lens itself. The ISO setting refers to the sensitivity of the camera's sensor to light; it adjusts the sensor's responsiveness rather than controlling the light directly entering the lens. White balance focuses on the color accuracy of the image and adjusts lighting conditions to create appropriate color temperatures, but does not influence the amount of light entering the lens.