The most probable reason for the construction of the road from IREWA through Sasi to the plantation is

The most probable reason for the construction of the road from IREWA through Sasi to the plantation is to evacuate farm products from the plantation to the market at IREWA. The road was likely built to facilitate the transportation of agricultural goods from the plantation to the market for sale. While the other options may have been factors in the decision to build the road, the transportation of farm products is the most likely primary reason for its construction.