Question

The carbon footprint of an activity is used to assess environmental pollution. What does it measure?

Answer 1

Honestly, you'd measure all of them but when people talk about cars, A/C units, or anything like that, it would be nitrogen oxide. green house's don't produce as much of a foot print mainly because they house plants which provide oxygen but they are filled with carbon monoxide so if you have any other information that would help but if not, I'd go with A