The state is planning to cut down old trees in a town to build new road. Many citizens in the town do not want the trees to be cut down. What should the citizens do to solve this problem?

C. Write letters to their state representatives and ask them to save the trees.

Explanation:

As it is said that it is the state who is planning to cut down the trees, the citizens should refer their state representative directly to try to refute the decision of cutting down the trees.

All other actions would either be referring to lower administrative bodies which do not have say in the decision or self initiate the result which won't change to state decision.