Answer: B. Water breaks down into oxygen molecules for respiration.
Water is the required for photosynthesis, a process by which plants (terrestrial and aquatic) makes their food by utilizing water as a reactant to produce oxygen and glucose as product. The glucose act as a source of energy for conducting various metabolic processes in plants but oxygen is released in the air.

This oxygen is necessary for terrestrial and aquatic animals for respiration. Therefore, water breaks down into oxygen by the process of photosynthesis, hence water plays important role in respiration in living beings.
Classic conditioning
a learning process that occurs when two stimuli are repeatedly paired; a response that is at first elicited by the second stimulus is eventually elicited by the first stimulus alone.
Explanation:
Frog undergoes a complete metamorphosis. It includes the egg, tadpole, froglet and then adult frog stages. In complete metamorphosis the hatchling does not resemble the parent and changes as it grows to be an adult.
During metamorphosis the tadpole will develop back legs first, then front legs. Around 6 weeks of life the mouth starts to widen. Sometime around 10 weeks the froglet’s, as it is now called, eyes start to bulge out and the tail begins to shrink and eventually disappear. When the lungs finish developing the froglet makes it’s way onto the land and, Ta-da! It’s a frog!
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