I haven't learned about diameter yet but I think you have to convert 2.86 and 2.94 into fractions and then see if any of those choices are in between those.
Convert each fraction in decimal, all of them mixed fractions, they have a integer part and other is a fraction. For converting a miexd fraction you have to add the integer + the fraction, for example 2 7/8 = 2+7/8= (applying adding fractions of different denominator) 2.875. So if you solve all of the mixed fraction you will get the answer is "A"
