In a Midterm Exam, a Student Was Asked the Following

In a midterm exam, a student was asked the following question: "Briefly list and explain the1 various components of Canada's class system as discussed by Daniel Rossides". As an answer the student wrote the following:
"The class system in Canada as described by Rossides includes four social class levels. The first is the upper class, an elite group limited to the wealthy, the majority of which are white. The second is the upper-middle class, composed of less affluent professionals, owners of small businesses and many white collar workers. The third is the lower-middle class, composed of clerical workers. Most do not hold post-secondary degrees but they do share the goal of sending their children to college or university. The fourth is the working class composed of blue-collar workers such as electricians and auto-industry workers". How would you judge this student's answer?

A) Good (all components discussed, but the explanations are not as clear as they should be)
B) Mediocre (a component is missing and/or the explanations are not clear or are irrelevant)
C) Excellent (all components discussed with clear and correct explanations)
D) Unacceptable (more than one component is missing and the explanations are unclear and/or are irrelevant)