Problem Statement: A few students are discussing a top that is spinning vertically in one place, but the rotational speed is slowing down. Which student$($s$)$ do you agree with?

$(1)$ If you look at a FBD for the top, there is no net external force, thus the velocity of the center of mass is constant.

$(2)$ The angular velocity of the top is changing, so there must be a non$-$zero net external force acting on the top.

$(3)$ I agree that there is no net external force, but since the angular velocity is changing there must be a net external torque on the top.