Concept:Cover crops are plants grown mainly to protect and improve the soil rather than for harvest.
Explanation:Cover crops form a dense ground cover that reduces soil erosion and suppresses weed growth.
They also add organic matter and help improve soil fertility, especially leguminous cover crops.
Centrosema pubescens and Mucuna utilis are both legumes widely used as cover crops in agriculture.
They fix nitrogen in the soil and are often planted in plantations or fallow lands.
The other options contain trees, pasture grasses, or weed species, so they are not typical cover crops.
Answer:A. Centrosema pubescens and Mucuna utilis