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

.

Therefore, the answer is (D)