When doing his homework, a student uses the addition property of equality to solve for c below. Which statement BEST applies to the sample? 6 + c = 10 6 + (–6) + c = 10 + (–6) c = 4 A. The student failed to keep both sides of the equation balanced. B. The student’s final answer does not have the variable c isolated. C. The use of the addition property of equality is sound, and the answer is correct. D. The student should have used the subtraction property of equality.