AMC 12 2007b Problem 4

At Frank's Fruit Market, 3 bananas cost as much as 2 apples, and 6 apples cost as much as 4 oranges. How many oranges cost as much as 18 bananas?

$\mathrm {(A)} 6 \mathrm {(B)} 8 \mathrm {(C)} 9 \mathrm {(D)} 12 \mathrm {(E)} 18$