A major challenge to agriculture in Manipur is:

The correct answer is: All of the above.

Limited availability of arable land: Manipur is a mountainous state with a relatively small area of arable land. This is a major challenge to agriculture in the state, as it limits

Lack of irrigation facilities: Manipur also suffers from a lack of irrigation

Poor market access: Manipur is also a landlocked state, which means that it has poor market access. This makes it difficult for farmers to sell their produce at a good price.

All of these factors contribute to the challenges faced by agriculture in Manipur.