What may become unbalanced if the rate of breathing is too fast or too slow?
Options:
- (A) meiosis
- (B) rain levels
- (C) photosynthesis
- (D) blood acidity
- (E) an organism's body
- (F) Veins and arteries.
- (G) kinetic energy
- (H) swamp vegetation OK. Let's think hard:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Blood pH may become unbalanced if the rate of breathing is too fast or too slow. Acidity is measured with a pH meter or with pH paper strips. Blood acidity may become unbalanced if the rate of breathing is too fast or too slow.
So, the final answer is (D).