Which statement is TRUE about sail shape?

A
A high-aspect ratio marconi mainsail is more efficient for downwind sailing than a gaff-rigged mainsail.
B
You should put more belly in a sail in light airs than in a strong breeze.
C
You can reduce the belly in a boomed mainsail by easing the sheet.
D
You can move the belly up in a mainsail by easing the luff tension.
E