using arm to prevent an opponent from attacking the ball

[ysong]

Would you please help me out on this, even if you think it is too simple?

Is an offensive player allowed to raise his non-shooting arm **within his vertical plane** as a shield to prevent an opponent from reaching the ball while the offensive player is trying for goal with another hand?

NCAA rule does not mention shooter's vertical right at all in this artical:

Personal Fouls
Section 18. By Players
Art. 5. A player shall not use the forearm and hand to prevent an opponent from attacking the ball during a dribble or when trying for goal.

Thanks a lot.

ysong