Question

question 67
carbon returns to the atmosphere:
a as carbon dioxide
b from respiration of plants
c from respiration of animals
d all of these are correct
e by the burning of fossil fuels

Explanation:

• Option A: Carbon is released to the atmosphere as carbon dioxide ($\ce{CO_2}$) through processes like respiration and combustion.
• Option B: Plants respire, breaking down organic matter and releasing $\ce{CO_2}$ into the atmosphere.
• Option C: Animals respire, producing $\ce{CO_2}$ which is released to the atmosphere.
• Option E: Burning fossil fuels (like coal, oil) releases carbon stored in them as $\ce{CO_2}$ into the atmosphere.

Since A, B, C, and E describe valid ways carbon returns to the atmosphere, option D ("All of these are correct") is accurate.

Answer:

D. All of these are correct