Respuesta :

108/9=12 is correct
78/5 and 22/5 added together is 100/5 which is 20.
6 4/7 - 4 3/7 cannot be 10 1/7 because you are subtracting not adding.
11/3 is 9 2/3 not 4 1/3
12*9=108 there for 108/9=12 

Answer:

C is it :D 108/9 = 12 is C

hopes this help :P