Concept:At Nigerian independence in 1960, agriculture was the backbone of the economy.
Explanation:Before the oil boom, Nigeria relied heavily on cash crops for revenue and exports.
Cocoa was the leading export crop, especially from the Western Region.
Therefore, cocoa provided the main financial support for the economy at that time.
Crude oil was discovered in 1956 but did not become dominant until the late 1960s and 1970s.
Thus, the mainstay of the Nigerian economy at independence was cocoa.
Answer:B. Cocoa