Only choices A & B are strong contenders.
One of the reasons I didn't choose A is that it concludes flights are a major contributor to air pollution. The only comparison we have is between flights and whole of Africa. But we don't know if Africa is a major contributor to air pollution. Sure comparing carbon emission by flights to a continent's is promising but what if Africa only contributes say 2% to total pollution and flights contribute only 2.1%?
Choice B is my answer
One of the reasons I didn't choose A is that it concludes flights are a major contributor to air pollution. The only comparison we have is between flights and whole of Africa. But we don't know if Africa is a major contributor to air pollution. Sure comparing carbon emission by flights to a continent's is promising but what if Africa only contributes say 2% to total pollution and flights contribute only 2.1%?
Choice B is my answer
.jpg)
