|18 + 7| / 10 is equal to 25/10
|-16 + 26| / 6 is equal to 10/6
25/10 can be multiplied by 3 to get 75/30
10/6 can be multiplied by 5 to get 50/30
75/30 - 50/30 = 25/30 and that simplifies to C) 5/6