Answer:
Option C
Explanation:
[a+b , b+c, c+a]
= (a+b).[(b+c) x (c+a)]
= (a+b).[b x c +b x a+c x c+ c x a]
= (a+b).(b x c +b x a+ c x a)
[$\because$ c x c=0]
= a.(b x c)+ a.(b x a)+a. (c x a)+ b. (bx c)+b. (b x a)+b.(c x a)
=a.(b x c)+b. (c x a)
=[a b c]+[a b c]
=2[a b c]
