which of the following human activities would be expected to be the biggest contributor to air…

Brief Explanations:

Driving vehicles, especially those with internal combustion engines, emits pollutants like carbon monoxide, nitrogen oxides, particulate matter, etc. Restaurant garbage mainly contributes to waste management and potential soil/water pollution (if not handled properly) rather than being a major air - pollution source. Aerosol cans (though some older ones with CFCs were bad for the ozone layer) are not as widespread a contributor to general air pollution as driving. Nuclear weapons are used in specific, rare (fortunately) events (like testing or war) and not a regular, large - scale contributor to air pollution compared to the daily activity of driving.

Answer:

A. driving