What is the best title for this passage

A．People who want to take their own lives often disguise their feelings.
B．It is difficult to describe what kind of people tend to commit suicide.
C．Suicide has been a problem in most cities since ancient times.
D．People who commit suicide all share certain characteristics.

A．The classical Greeks did not know the existence of suicide.
B．Suicide has always been prevalent in all parts of the world.
C．In today' s society, there are quite a number of people who commit suicide.
D．Nowadays suicide is not as common as it was in the past.