Which of the following statements DOES NOT answer the question“What caused the life-sav-ing effect to occur in the early 1990s?”
A.
There were more cell phone users d uring that period.
B.
The number of eelI phone users reached about 100 million.
C.
More cell phones were used to call 911 when accidents occurred.
D.
Cell phones enabled people to have quick access to 911 services.