I believe it to be C
Explanation: The concentration of carbon dioxide in Earth’s atmosphere is currently at nearly 412 parts per million (ppm) and rising. This represents a 47 percent increase since the beginning of the Industrial Age, when the concentration was near 280 ppm, and an 11 percent increase since 2000, when it was near 370 ppm.
If it is shown as ∆H , then it means that a specific chemical reaction is undergoing heat in Kelvin(K). If it is shown as ∆H° , then it means that a specific chemical reaction is undergoing heat in Celsius(C⁰).
Hope this is the answer you are looking for mate!
If it is correct then please mark my answer as the brailiest! :)
