offensive foul, defensive foul or no call?

[thereluctantref]

Another question...

Player A is driving to the basket. He drives all the way to the low block where the defender is waiting with arms raised, holding his position. Player A drives all the way until he can't penetrate anymore because of the defender's position. He puts up the shot and makes contact with the raised arms of the defender who is still with arms totally vertical. Defender doesn't want to move, to reach in or slide to defend and make contact to foul.

Is this a foul on the defender, Player A or no call?