The tension in the string with friction would be the biggest because of the involvement of the force of gravity. This would result in that the friction force that is acting on the system. There is no friction in the frictionless system, and only the force of gravity is relevant.
Answer: The first one
Explanation: I think it's the first one because it says what is the "least" gravitational potential energy story between the prairie dog and Earth that said resting in its borrow is using less energy
