Q: When did we learn there was a hole in the ozone layer?


Read this paragraph and choose the correct option from the provided answers:

Ozone near the ground harms human health. Ground-level ozone is a pollutant. But the ozone layer in the stratosphere protects us from harmful solar rays. That’s why people were alarmed in the 1980s to learn that there was a hole in the ozone layer.

 Choices:

- 1950s

- 1970s

- 1990's

- 1980s


A:
1980s