First we can simplify 4/6 dividing between two on numerator and denominator
then 2/3 and 4/3 are the same number, then option A and -b are wrong the number are the same and cant be greater or less than
we can notice on second number line 4/6 is less than 5/6 then 2/3 is less than 5/6 too
then right option is C