Fact 1: Breathing is when a gill converts from oxygen in water into oxygen in blood. Fact 2: Hemoglobin transports oxygen in blood. Given the two facts above, breathing is when a gill converts from oxygen in water into?

Choose your answer from:
(i) tiny polyps.
(ii) Hemoglobin.
(iii) salmon.
(iv) motility.
(v) unidirectional.
(vi) exoskeleton.
(vii) heat energy.
(viii) epidermal.
Answer:
(ii)