(c) find the longest interval during which no tree-cutting samples occurred. what is the first year that no tree-cutting samples occurred in that interval?

Longest interval during which no tree-cutting sample occurred: 9 years (1203 AD - 1212 AD)

First year in that interval: 1203 AD

Explanation:

Lets complete the question first.

Q) A study uses tree rings to determine the year in which a tree was cut. The data is shown in the leaf and stem diagram in the ATTACHMENT.

The three digits number in the left column represents centuries and decades AD. The numbers on the right represents the years.

For example, consider the first input in the diagram

119 | 5   6

which means it represents 2 samples.

1195 AD, 1196 AD.

The longest interval with no tree-cutting samples is found from 1203 AD to 1212 AD.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.