How Are Tree Rings Used as Proxy Data to Provide

How are tree rings used as proxy data to provide an indirect record of past climate conditions?

A) Tree rings are thicker and the wood is denser when growing conditions are better.
B) Tree rings are thicker and the wood is lighter when growing conditions are better.
C) Tree rings are thinner and the wood is denser when growing conditions are better.
D) Tree rings are thinner and the wood is lighter when growing conditions are better.
E) Because of variable moisture levels, tree rings cannot be used as proxy data.