An iodine test of a tomato plant leaf revealed that starch was present at 5: 00 p. m. on a sunny afternoon in july. when a similar leaf from the same tomato plant was tested with iodine at 6: 00 a. m. the next morning, the test indicates that less starch was present. this reduction in starch content most likely occurred because starch was: . changed directly into proteins b. transported out of the leaves through the guard cells c. transported downward toward the roots through tubes d. changed into simple sugars