<span>B. The writer can use the ideas of others without having to cite the source.</span>
Jin Wang would be the best example.....
The correct answer is A. This is the case of using comma before a coordinating conjunction <em>and</em> because it links two independent clauses. We can observe that there two parts of this full sentence and each part is independent from each other. Both of them have their own subject and verb. Therefore, we are using a comma before <em>and</em>.
