To determine if Switch Grass will grow in the region of Africa based on the soil type, we need to know the specific soil composition from the region referenced in the graph. If the soil sample contains at least 25% clay and/or silt, then Switch Grass would be suitable for growth.
Without the actual graph or soil sample data to refer to, it isn't possible to provide a definitive answer.
Thus, the correct choice based on the provided information is:
Not enough information.