A farmstand sells apples, a, for $4 a bucket; peaches, p, for $6 A bucket; and strawberries, s, for $9 a bucket. The stand earn $229 in revenue last month. The stand sold half as many strawberry buckets as peach buckets, and eight were apple buckets then peach buckets. Using the substitution method how many apples peaches and strawberries did the farmstand sell?
A. a=10; p=18; s=9
B. a=4; p=6; s=9
C. a=18; p=10; s=9
D. a=9; p=18; s=10