Why Is It Recommended That Canadians Consume One Dark Green

Why is it recommended that Canadians consume one dark green and one orange vegetable daily?

A) Because green vegetables are high in folate and orange vegetables provide vitamin A.
B) Because green vegetables are high in vitamin C and orange vegetables provide calcium.
C) Because green vegetables are high in vitamin K and orange vegetables provide iron.
D) Because green vegetables are high in vitamin B₁₂ and orange vegetables provide potassium.