Abhi covered a leaf of a potted plant and kept the plant under sunlight for a few days and then tested it with iodine solution for the presence of starch in it. The colour of the covered leaf did not turn blue-black. What does this indicate?

• A.  The black cover absorbed all the starch present in the leaf.
• B.  Iodine solution does not work with black covers.
• C.  Starch is evaporated from the leaves.                        
• D.  Starch is prepared only in the presence of sun light.