The correct answer is: Only conclusion II follows.
The first statement is “All trucks fly.” This means that every truck is a flying object. The second statement is “Some scooters fly.” This means that there are some scooters that are flying objects.
From these two statements, we can conclude that some scooters are flying objects. However, we cannot conclude that all trucks are scooters. This is because the first statement only says that all trucks fly, not that all flying objects are trucks. It is possible that there are other types of flying objects besides trucks.
Therefore, only conclusion II follows. Conclusion I does not follow because it is not supported by the evidence.