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:_______a. 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