The correct answer is: Only conclusion II follows.
The first statement is “All cars are cats.” This means that every car is a cat. The second statement is “All fans are cats.” This means that every fan is a cat.
The first conclusion is “All cars are fans.” This means that every car is a fan. However, this conclusion does not follow from the premises. The premises only say that all cars are cats and all fans are cats. They do not say that all cats are cars or that all fans are cars.
The second conclusion is “Some fans are cars.” This means that there is at least one fan that is a car. This conclusion does follow from the premises. The premises say that all cars are cats and all fans are cats. This means that there is at least one car that is a cat. Therefore, there is at least one fan that is a car.
Therefore, the only conclusion that follows from the premises is “Some fans are cars.”