This Plot of Ice-Core Data Shows Measurements of CO₂ Content

This plot of ice-core data shows measurements of CO₂ content and interpretation of temperatures. These data show:

A) that CO₂ concentration and temperature generally increase and decrease over the same time periods
B) that most temperature changes on this graph are due to CO₂ introduced by humans
C) that current temperatures are the highest they have been
D) all of these