Predictions about climate change

Which is not a reason why scientists are limited in their ability to make predictions about climate change?

A. Extrapolation from past trends involves uncertainty.

B. Scientists are unable to make accurate measurements of gas concentrations in the atmosphere.

C. Scientists do not fully understand the interaction of the lithosphere, hydrosphere, and atmosphere in the movement of thermal energy.

D. The nature of natural cycles that occur over the centuries may not be adequately known.