Infield Fly or Intentionally Dropped Ball on a Bunt?

 
With the bases loaded and 1 out, the batter (B1) bunts a very high pop up to the pitcher. The pitcher easily settles under the ball but the catcher yells that none of the runners are moving off their base, so the pitcher lets the ball hit the ground untouched. All three runners then begin to advance towards their next base. The pitcher then throws to home where home plate is touched to easily retire the runner from third base. The ball is then thrown to third base, where third base is touched to easily retire the runner from second base.
 
The umpires were offered these rule interpretations from the helpful offensive and defensive coaches:

A) The pitcher intentionally dropped the ball, so B1 is out for the second out of the inning, the ball is dead, and all runners return to their bases. The inning continues with 2 outs and the bases loaded.
B) This is an infield fly. B1 is out for the second out of the inning, but any other runners must be tagged. Since no runners were tagged, one run scores and runners remain at third and second base.
C) The defense executed this double play properly -- inning over.
 
Call
It is not an intentionally dropped batted ball if the fielder allows the ball to drop untouched to the ground (NF 8-4-1c). Attempted bunts are not considered candidates for the infield fly rule (NF 2-19). On the play below, there is no need to read past the first 5 words of each answer. Since the situation below is not an intentionally dropped ball (answer "A"), nor is the infield fly in effect (answer "B"), the answer is "C" -- double play, inning over!