Which of these would lead to an increase in carbon dioxide in the atmosphere? A. a decrease in respiration
B. a decrease in the ozone layer
C. an increase in photosynthesis
D. an increase in the burning of fossil fuels

Please explain why you got the answer if you can.

D. an increase in the burning of fossil fuels

Explanation:

Carbon dioxide concentrations are rising mostly because of the fossil fuels that people are burning for energy. ... For 2018 alone, global fossil fuel emissions reached 10 ± 0.5 Pg C yr−1 for the first time in history (Friedlingstein et al. 2019). About half of the CO₂ emitted since 1850 remains in the atmosphere.

D

Explanation:

it's not that hard to understand. It puts carbon in the air, and it could destroy that atmosphere.