Answer the following question given this paragraph: 

Since the mid 1800s, Earth has warmed up quickly. Look at Figure below . The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming .


Q: Eight of the hottest years on record have occurred since what year?

 Choices:

- 2002

- 1997

- 1991

- 1998

A:
1998
