What is the main way that active transport differs from diffusion?

Active transport is different from diffusion because it requires energy expenditure, while diffusion requires no energy at all. In diffusion, materials are moving from areas of high concentration across the cell membrane into areas of low concentration. This requires no energy on the part of the cell. In active transport, however, the cell is moving material between two areas of equal concentration, or from an area of low concentration into an area of high concentration. This requires the cell to expend energy.

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.