Step 1: Draw a Venn diagram: the circle of pens lies completely inside the circle of books (All pens are books). Step 2: "Some books are tables" means the circle of tables overlaps the circle of books, but the overlap may be in the part of books that has no pens. Step 3: Conclusion I (Some pens are tables) is not certain, because the tables may overlap only with the non-pen part of books. So I does not follow. Step 4: Conclusion II is the simple conversion of "Some books are tables": "Some tables are books" is always true. So II follows. Answer: Only II follows.