Answer: The farmer included the tenth amendment in the Constitution to prevent Congress from having unenumerated powers over individual states.
Explanation: The tenth amendment is the final bill of rights, which states that any power not delegated (or authorized) by the Federal Government is reserved for the states. This means that if the government does specify any power or decision, the choice is left for the states to decide.
Example: An example of the tenth amendment would be the prohibition of drugs. The government does not explicitly say drugs are forbidden, so states therefore are left with the decision of whether or not to allow drugs.
The final answer: Answer B was included in the Constitution to prevent Congress from having unenumerated powers over individual states.