It is really difficult to answer this question based on provided data. Rather speculations can be made. This is because of several reasons. The height of plant varies for different plant species. Likewise, it is really difficult for any plant species to the height of 5 inches (the lowest given option) within period of 8 hours only. It needs 8 hours light for several days to reach this much of height even for studied model plants such as arabidopsis. Thereon, each plant species would need different number of days.
On the other hand, it is important to consider that sunlight is a vital parameter for plant cells to elongate and multiply. This is because of the fact that plant use sunlight to fix carbon dioxide into the carbohydrates which is used in many cellular processes including cell division and growth. However, metabolic machinery in different plants works at different rates. Based on these reasons, it is super difficult to pick one option out of the given information to answer this question. Hope this helps.
