Look at this expression. a3b3c a-3b-3c-1 Which of the following is the simplest form of the expression above? -1 1 a-6b-6c-2 a6b6c2?

Look at this expression. a3b3c a-3b-3c-1 Which of the following is the simplest form of the expression above? A. -1

B. 1

C. a-6b-6c-2

D. a6b6c2?