Plants release ___ in photosynthesis.

**The reasoning** Photosynthesis is the process where plants make their own food using sunlight. The word equation is: **Carbon dioxide + Water → Glucose + Oxygen** (CO₂ + H₂O → C₆H₁₂O₆ + O₂) Plants *take in* CO₂ from the air through their leaves and water from their roots. Using sunlight energy (captured by chlorophyll), they combine these to produce glucose (their food) and release **oxygen (O₂)** as a byproduct. This is why forests are called "the lungs of the Earth" — they're constantly pumping out the oxygen we breathe! **Why the wrong options tempt you** - **A) CO₂** — This is what plants *absorb*, not release. Easy mix-up if you confuse inputs with outputs. - **B) N₂** — Nitrogen gas makes up 78% of air, but plants don't release it during photosynthesis. - **D) H₂** — Hydrogen is in water (H₂O), but it's not released as gas; it becomes part of glucose. **Quick takeaway** Remember: Plants breathe *opposite* to us — they take in CO₂ and give out O₂, which is why we need them to survive!