Help plz it’s homework

The right option is 'B' i.e air pollution.

Hope it helps you.

there are two main types of historical sources: primary sources and secondary sources. a primary source is something that originates from the past. it can be a chronicle, a piece of pottery, or even a piece of glacial ice that gives us climate data about the levels of atmospheric carbon one thousand years ago.

honestly you should get that checked out because it really isn't normal