Alpha Can Produce Either 18 Tons of Oranges or 9

Alpha can produce either 18 tons of oranges or 9 tons of apples in a year, while Omega can produce either 16 tons of oranges or 4 tons of apples in a year. Which of the following terms of trade would allow both Alpha and Omega to gain from specialization and trade?

A) 1 ton of apples for 3 tons of oranges
B) 1 ton of apples for 2 tons of oranges
C) 1 ton of oranges for 0.5 tons of apples
D) 1 ton of oranges for 0.2 ton of apples
E) 1 ton of apples for 4 tons of oranges