Choice D is a possible equation of the polynomial.
A function’s roots are determined when y=0 such that an equation for x input will generate y=0 output. In other words, the roots are where the function crosses the x-axis. Remember, when a function touches the x-axis, that root has multiplicity. When a function intercepts the x-axis at a point, there is multiplicity of 1. Therefore roots -3 and 2 touch the x-axis, so there is multiplicity of 2. The root -1 intercepts the x-axis, so it has multiplicity 1.