Concept:This question tests knowledge of common names of pasture grasses.
The scientific name provided must be matched with its known agricultural name.
Explanation:The grass
Andropogon gayanus is widely known as Northern gamba grass.
It is a robust tropical forage grass.
Farmers use it for livestock grazing and fodder production.
Its strong growth in tropical savanna regions makes it popular.
The other options belong to different species of grass.
Elephant grass, Guinea grass, and giant star grass have distinct botanical identities.
Therefore, the correct common name for this grass is Northern gamba grass.
Answer:B. Northern gamba grass.