need help answering the question below requires the knowledg

need help answering the question below requires the knowledge of SolidWorks please explain your answers
thanks

Rigid body modes. Choose all that are correct occur at negative frequencies EM occur at zero frequency only occur if the model has insufficient supports. l can only occur in an assembly, have no physical meaning

Solution

Rigid body modes occur, if the motion can occur in any of the six-degrees of freedom(3 translation in X, Y and Z and 3 rotational about X, Y and Z) i.e. the motion in six degree of freedom can only occur if the model has insufficient supports.

The rigid body in a model will have natural frequency close to zero or 0.