Which gas is produced during photosynthesis that directly benefits humans?

• A. Oxygen (\(O_2\))
• B. Methane (\(CH_4\))
• C. Carbon dioxide (\(CO_2\))
• D. Nitrogen (\(N_2\))

Answer: (A)

Verified step by step guidance

1. Step 1: Recall the process of photosynthesis, which occurs in plants, algae, and some bacteria. During photosynthesis, light energy is converted into chemical energy, and the reactants are carbon dioxide (\(CO_2\)) and water (\(H_2O\)).
2. Step 2: Understand the chemical equation for photosynthesis: ${\mathrm{6CO}}_2+{\mathrm{6H}}_{2}O\to C_6{H}_{12}{O}_6+{\mathrm{6O}}_2$. This shows that oxygen (\(O_2\)) is a byproduct of photosynthesis.
3. Step 3: Recognize that oxygen (\(O_2\)) is essential for human survival because it is required for cellular respiration, the process by which cells generate energy.
4. Step 4: Eliminate the other options: Methane (\(CH_4\)) is not produced during photosynthesis, carbon dioxide (\(CO_2\)) is consumed rather than produced, and nitrogen (\(N_2\)) is not involved in the photosynthesis process.
5. Step 5: Conclude that the gas produced during photosynthesis that directly benefits humans is oxygen (\(O_2\)).