The ratios as fractions are 6/8 and 9/11.
Since they are not compare because they have different denominators you must find the Least Common Multiple of the two fractions.
Since 8 and 11 both can go into 88, we can use that as our denominator.
6/8 times 11/11 equals 66/88 and 9/11 times 8/8 equals 72/88.
66/88 is less than 72/88.
Therefor, Mix B is the reddest mixture.
Hope this helped!! :)