As Input for a Presentation That You Are Jointly Authoring

As input for a presentation that you are jointly authoring, one of your marketing analysts submitted the following summary of the characteristics of the four different types of market structures companies compete in:
With respect to the classifications of number of competitors and barriers to entry, which one of the following statements is correct?

A) The monopolistic competition structure is properly classified.
B) The monopoly and oligopoly structures' classifications should be reversed.
C) The monopoly structure is properly classified.
D) The oligopoly structure is properly classified.
E) The pure competition and oligopoly structures are properly classified.