The inaccurate explanation is:
The difference in the mass is not significant and will not affect the force needed to throw the ball 85 mph.
This statement is incorrect because the increase in mass from 145 grams to 200 grams is a significant change, which would indeed require more force to throw the ball at the same velocity of 85 mph. The other statements correctly describe the relationship between force, mass, and acceleration according to Newton's second law of motion.