The likely advantage of growing a genetically modified variety of tomato that remains fresh over several days is that post-harvest losses due to delayed transportation would be reduced.
Tomatoes are a perishable crop that are susceptible to spoilage and decay during transportation and storage. By developing a genetically modified variety of tomato that remains fresh for longer periods of time, farmers and distributors would be able to extend the shelf life of the tomato and reduce the amount of waste due to spoilage. This would also allow for longer transportation times and greater distances to be covered, leading to more efficient distribution and potentially lower costs for consumers.
The other options listed are not likely advantages of growing a genetically modified variety of tomato that remains fresh over several days. Disease-causing pests may still be able to attack the variety, and the nutritional content of the tomato would not necessarily be altered. Similarly, the variety would not be expected to improve the quality of life of people with genetic disorders.