Question for Wednesday

The diagram below shows an example of interdependence among aquatic organisms. During the day the organisms either use up or give off (a) or (b) as shown by the arrows.

 

 

Choose the right answer for (a) and (b) from the alternatives given.

 A)(a) is oxygen and (b) is carbon dioxide.
 B) (a) is oxygen and (b) is carbohydrate.
 C) (a) nitrogen and (b) is carbon dioxide.
 D)(a) is carbon dioxide and (b) is oxygen.
 E)(a) is carbon dioxide and (b) is carbohydrate.