Answer:
Answer is A. Learning by doing.
Step-by-step explanation:
In the far olden days, during the colonial era, the farmers only improve on their productivity through the process of doing it. This involves trial and error process. It is so because, there wasn't technology and no form of modern education that will help them to carry out research before execution, they only depend on their instincts. This means that, they execute what they think and learn from it.