Runner or Fielder -- Who Has the Right of Way?


 
With one out and a runner on 2nd base (R2), the batter (B1) hits a high pop-up half-way between home and 1st base and very near the foul line. The pitcher is standing on the foul line ready to catch the pop-up. B1 is running (head down in the runner's lane) and accidentally runs into the pitcher and prevents him catching the pop-up. R2 advanced to 3rd base during the play. What is the call?
 
A) Play on -- both the fielder and batter-runner were where they were suppose to be and the contact was accidental.
B) B1 has a right to run directly to 1st base, especially since he was in the runner's lane. The pitcher obstructed B1, so award B1 first base, if he was not called safe at 1st base.
C) The fielder is protected when fielding a batted ball, so B1 interfered and is immediately out.
D) R2 must return to 2nd base.
E) R2 may remain at 3rd base.
F) The umpire's call depends on whether the pop-up was ruled fair or foul by the plate umpire.
 
Call
In this situation, the pitcher was making the initial play on the batted ball, so the pitcher is protected from interference by the B1. B1 is out for his interference and R2 must return to second base (answers "C" and "D").