Which of the following statements correctly explains why the equation: $a(b-c)=ab-ac$ is written in terms of treating subtraction as an addition of a negative?

• A. Because only the first term inside parentheses is multiplied and the second term remains unchanged, so $a(b-c)=ab-c$
• B. Because subtraction implies division by $-1$ before distribution, leading to $a(b-c)=\frac{ab}{-1}-\frac{ac}{-1}$
• C. Because subtraction inside parentheses changes the sign of the outside multiplier to positive, so $a(b-c)=ab+ac$
• D. Because $b-c$ is the same as $b+(-c)$, and distributing gives $ab+a(-c)=ab-ac$