Concept:Use Venn diagrams to check logical validity of conclusions.Explanation:Statement I: Some rats are cats → there is at least one rat that is a cat.Conclusion I: "No rats are cats" directly contradicts Statement I, so it does not follow.Statement II: All cats are bats → the set of cats is inside the set of bats.Since some rats are cats, those rats are also bats → some rats are bats.Thus Conclusion II logically follows.Answer:Only conclusion II follows.