According to the given information, the least possible diagram is as follows:
Conclusions:I. No stump is a ball - False (As we don't know the relation between stumps and balls, we can't say "No stump is a ball") II. No ball is a stump - False (As we don't know the relation between stumps and balls, we can't say "No ball is a stump") III. Some balls are bats - True (As "All bats are balls" some balls will definitely be a bat) IV. All the balls are bats - False (As "All bats are balls" we can't say "All the balls will definitely be a bat") Hence, the correct answer is "Only conclusion III follows".