Which of the following best describes a system consisting of a rotating unbalanced mass m with eccentricity?
A. The system's center of mass is located at the center of rotation.
B. The system exhibits balanced rotational behavior due to the unbalanced mass.
C. The eccentricity causes the system to have a net force of zero during rotation.
D. The system experiences an imbalance, resulting in a non-zero net force during rotation.