This question has three statements and each statement is further divided into three segments. Chose the alternative where the third segment in the statement can be logically deduced using both the preceding two, but not just from one of them.
A: Some substances are crystalline. Marble is crystalline. Marble is a substance.
B: All greyhounds are dogs. Some dogs are cows. Some greyhounds are dogs.
C: All locks are keys. Some keys do not open. Some locks do not open.
