I would go with A. Make certain the pusher prop is mounted correctly (rounded edge of prop is the Leading Edge and points to the direction of rotation). Remember that in a pusher application the engine will overheat if it is not in the air flying. I get my pusher Canard into the air within 30 seconds of engine start. For engine tuning I replace the prop with a tractor prop of the same make, diameter, and pitch. Good luck. Post your maiden flight report.