Which of the following is not mentioned as a motive for suicide

A．relevant
B．kind
C．serious
D．effective

A．a network of centers has been quite effective in reducing suicide
B．a network of centers help the callers to realize that suicide is a common social problem
C．people are making efforts to help those who tend to commit suicide and in a way, they are successful
D．in the US, people who want to commit suicide call a network of centers to get help