The correct answer is B) He set aside his qualms about the government's powers under the Constitution in order to purchase the Louisiana Territory.
Before Jefferson became president, he was a significant advocate for a strict interpretation of the US Constitution. This means that if the power is not directly given to the federal government in the US Constitution, than the federal government cannot perform that action. By this logic, the US federal government could not buy land from foreign countries. However, when Jefferson became president, he had the opportunity to buy 800,000 square miles of land from France in North America for a relatively cheap price. This is when Jefferson started to favor a loose interpretation of the Constitution, meaning this document was flexible in what powers the federal government could possess.
I believe the answer is: B) He set aside his qualms about the government's powers under the Constitution in order to purchase the Louisiana Territory.
Thomas Jefferson was known to has a strict interpretation of the constitution. Which mean that unless a power is expressly listed in the constitution, the government shall never allowed to do it.
But, even though the power to acquire other territory does not expressly listed, Jefferson decided to overlook his principle and asked the Congress to pass the treaty to aid Him purchase the Louisiana territory.