Casey has buckets of 3 different sizes. The total capacity of 12 of the buckets is g gallons, the total capacity of 8 buckets of another size is g gallons, and the total capacity of 4 buckets of the third size is also g gallons. In terms of g when g>0, what is the capacity, in gallons, of each of the smallest-sized buckets?
A. g/12
B. g/8
C. g/4
D. 12g
E. 8g