Lanie Had an Asthma Attack While Attending a Rock Concert

Lanie had an asthma attack while attending a rock concert. The crowd was focused on the noisy act onstage. What is the most likely reason that no one helped her

A) No one noticed her distress.
B) Concert goers aren't very responsible.
C) No one in the audience was capable of getting help.
D) People felt like the cost of helping was too great.