B is not the same logic as that given by the stimulus. I'll explain.
If Max were guilty, he would not ask the police to investigate. G - - - - - - - - > not API
This does not mean that he will certainly ask the police to investigate if he's not guilty. We know that it is possible, but it is not certain. That is why not G - - - > API is not a valid statement. We cannot simply move the "not" from one side to the other. This represents a misunderstanding of sufficient and necessary conditions.
Here is the proper contrapositive, representing the same logic as the stimulus. API - - - - -> not G This is a claim that we can make with certainty. If Max asks the police to investigate, then we know he is not guilty.
