All farmers were encouraged _______carry out fumigation on their farms.
Answer Details
The best option to complete the sentence is "to".
"Encouraged to" is a common phrase used to indicate that someone is motivated or persuaded to do something. In this case, the sentence is saying that the farmers were motivated to carry out fumigation on their farms. The word "encouraged" implies that someone (perhaps an authority or expert) advised or recommended that the farmers perform fumigation for some reason, such as to prevent pests or diseases from damaging their crops.
Therefore, the complete sentence would be: "All farmers were encouraged to carry out fumigation on their farms."