In the question three statements are given, followed by three conclusions, I, II and III. You have to consider the statements to be true even if it seems to be at variance from commonly known facts. You have to decide which of the given conclusions, if any, follows from the given  Statements.
Statement I: No marble is granite
Statement II: All stones are marble
Statement III: Some rocks are stones

Conclusion I: Some rocks are granite
Conclusion II: Some marble are rocks
Conclusion III: No stones are granite