Concept:Growing two or more crops on the same piece of land during the same season is known as mixed cropping.
Explanation:Cowpea and maize are two different crops planted together on the same land at the same time.
This simultaneous cultivation of more than one crop on the same field is the defining feature of mixed cropping.
Mixed farming, on the other hand, combines crop production with livestock rearing on the same farm.
Crop rotation involves growing different crops in a planned sequence over different seasons on the same plot.
Land rotation is not the correct term for this simultaneous practice.
Therefore, the practice described in the question matches the definition of mixed cropping only.
Answer:B. mixed cropping.