Answer:
See below.
Explanation:
Assuming the ratio 6:1 is blueberries to sugar then this means 6 cups of blueberries is used for each cup of sugar.
A. If one cup of blueberries is used then 1/6 cup of sugar should be used.
B. No information is given here about butter.
C. If one cup of sugar is used the 6 cups of blueberries are needed.