Concept:Low farm output is the main cause of poverty in West African agriculture.
Explanation:Most farmers in West Africa record relatively low yields each year.
These low yields lead to small incomes and poor living conditions.
Joining cooperative societies and having credit access are support measures, not causes of poverty.
They are intended to improve farming, not make farmers poor.
Unpredictable weather is a challenge, but the core issue is consistently low production.
Therefore, the agricultural sector remains poor because annual yields are low.
Answer:B. yields obtained per annum are relatively low