Assuming $a \neq 3, b \neq 4$, and $c \neq 5$, what is the value in simplest form of the following expression? (Adapted From 2020 AMC 10A Problems, Question \#3)  $$ \frac{2a-6}{5-c} \cdot \frac{b-4}{3-a} \cdot \frac{2c-10}{4-b} $$ 
选项为:A:$$2$$  B:$$-4$$  C:$\frac{a b c}{15}$  D:$\frac{4}{a b c}-\frac{1}{15}$  E:$\frac{1}{15}-\frac{1}{a b c}$  请回答其中一个选项.