The graph below shows the number of sunspots observed between 1750 and 2000. The graph shows sunspot number on the y axis and years 1750, 1800, 1850, 1900, 1950, and 2000 on the x axis. The graph rises and falls in a cyclic order in gaps of approximately 10 years. The number of sunspots in 1800 was 10. The number of sunspots observed in 1850 was 130. The number of sunspots in 1900 was 15. The number of sunspots observed in 1950 was 150.

Based on the graph, which of these statements is most likely correct about the period between 1900 to 1950?

There was a decrease in global temperatures.
There was an increase in global temperatures.
There was no significant change in global climate.
There was no significant change in solar activity.