the amount of blueberries is the subtraction of the total weight and the weight of each ingredient
then

first we transform the mixed numbers to be earlier the work

I transformed 8/2 to 10/4 to make easlier the operations(I just multiply by 2 on numerator and denominator and the fraction is equivalent)
now make the subtract

the amount of blueberries is 1 1/4 then right options is A 1pound because is the best estimate