Question 1Which of the following expressions is equal to $(a+1)(b-1)+(b+1)(c-1)+(c+1)(a-1)$?$ab+bc+ca-3$$ab+bc+ca$$ab+bc+ca+2a+2b+2c+3$$ab+bc+ca-2a-2b-2c-3$$ab+bc+ca-2a-2b-2c+3$