The more the image resolution would be the more storage it needs. If you think about it when a website tries to load a large image it takes longer than loading a smaller one. Hence, if you have a slow telephone line and need your images to be displayed (loaded) faster, then you have to go with the smallest resolution (the smallest storage).
In a nutshell, your answer will be d) 320x240
Note: 320 x 240 is the dimensions of the image (width x height) and those numbers are measured in pixels which is the unit of measuring images, display screens,...etc. i.e. this image is 320 pixels in width and 240 pixels in height
The answer is yes I hope this help ya out
