which option identifies the best first method of determining possible crop yield in the following scenario? a farmer wishes to develop a new commercial crop, and intends to cultivate an old heirloom strain of corn that was common in the region until the mid-20th century. responses estimate based on the average yield of modern genetically modified seeds estimate based on the average yield of modern genetically modified seeds research usda records of crop yield of the period using similar seed in the same region research usda records of crop yield of the period using similar seed in the same region estimate based on the average yield of his own fields before changing seed type estimate based on the average yield of his own fields before changing seed type research yields by dedicating a field to the heirloom for several years to obtain an average