Sugar was added to either the cups marked A or the cups marked B. Given what you know about anaerobic respiration, which cup had the added sugar? Explain your answer in terms of the energy source(s) available to the yeast.

B

Explanation:

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.