I don't see in your hypo where B is distributing, but seems A is distributing in both scenarios. It's called "distributing" not "selling for profit". The prosecutor will evaluate each case to do justice in the prosecutor's mind. Some are strict, some are lenient. Depends on many things: their caseload, their political ambitions, the recalcitrance of the defendant, the skill of the defense attorney, etc.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.