What is the most expensive type of call

A．no heart disease will be found if people don't drink coffee
B．no one should drink more than two cups of coffee a day
C．the more coffee people drink, the more chance they will get to have heart disease
D．women's heart disease has something to do with their drinking of coffee

A．the mayor has agreed with the teachers' union
B．the teachers' strike will last long
C．students haven't been to school for two weeks
D．the mayor was trying to end the schools