Correct Option (B)
Assumption 2 is valid. The passage explicitly states that "a group approach to farming, especially in the form of bottom up agricultural production collectivises, offers substantial scope for poverty as well as enhancing agricultural productivity." This directly supports the assertion that agricultural productivity can be increased by a group approach to farming.
Incorrect Options:
Assumption 1 is not valid. The passage mentions "transition economies" as contexts where "many notable examples of such collectivises" are found. However, it presents them as examples of successful cooperation under given conditions, not as a mandatory or "imperative" requirement for these economies. The passage does not state that it is absolutely necessary for transition economies to have agricultural collectivises.