Look at the given equation. Roy and Sam start solving the equation as follows. Which student's work is correct so far and what property did he use? A. Roy's work is correct so far. He used the subtraction property of equality. B. Roy's work is correct so far. He used the addition property of equality. C. Sam's work is correct so far. He used the addition property of equality. D. Sam's work is correct so far. He used the subtraction property of equality.