The correct answer is B. They suspect something strange may be going on.
Step-by-step explanation
According to the fragment, it can be inferred that the central theme of the discussion between Charlie and Steve is about a strange fact that caught their attention and they are going to check what has happened. In addition, they discard the option that it was a meteorite as Steve says "It couldn't be the meteor. A meteor couldn't do this". According to the above, the correct answer is B because they can not explain the event that just happened.