It is A! He used a atmospheric perspective.
Yay thankssssssassssssssssssss
Exposure means how light or dark the image you took with your camera will come out which is determined by the exposure triangle which contain 3 camera settings(aperture, iso, and shutter speed)
as aperture increases the f-stop values, the lens shuts. as it decreases the lens opens
light is a factor in the exposure of the photograph. aperture must be calibrated so the image will be clear and focused
I'm not sure on the last one but I know that when the aperture is low itll be a fast lens and when its higher itl be a slow lens
I hope I helped :)
123, 1, 123, 12
12 4, 123, 1 34
1, 12, 1, 12, 12, 12
1 3, 12 , 123, 123
1 3 , 123 , 1 , 1 4
let me know if I wrote it confusingly