Billie's Billiard Barn Has Seen Its Business Slow Down Ever

Multiple Choice

Billie's Billiard Barn has seen its business slow down ever since Patti's Ping Pong Parlour opened up across the street.Since the opening of Patti's Ping Pong Parlour, the opportunity cost of shooting pool at Billie's Billiard Barn has ________ for Billie's customers who also like to play ping pong.

A) decreased
B) increased
C) fallen to zero
D) not changed