Answer:
C. 1700s
Step-by-step explanation:
How has the average temperature on Earth changed over time?
Earth's temperature has risen by 0.14° F (0.08° C) per decade since 1880, and the rate of warming over the past 40 years is more than twice that: 0.32° F (0.18° C) per decade since 1981. ... From 1900 to 1980 a new temperature record was set on average every 13.5 years; from 1981–2019, a new record was set every 3 years.