Question

the oxygen that we breathe in from plants is derived from:
○ glucose.
○ water.
○ sunlight.
○ carbon dioxide.

Explanation:

During photosynthesis, plants split water molecules ($H_2O$) in the light-dependent reactions, releasing oxygen as a byproduct. This oxygen is the source of the oxygen we breathe. Carbon dioxide is used for glucose synthesis, sunlight is energy, and glucose is a product—not the source of oxygen.

Answer:

B. water.