Which of the following is true about asbestos?

A) There are several types of asbestos, but they represent the same mineral.
B) Different types of asbestos have the same health risks.
C) Each type of asbestos has long, straight fibers.
D) Asbestos represents different minerals with different health risks.

Which statement represents current food production? 

A)  Input of labour required per unit of food has increased. 
B)  Food output in Canada has decreased. 
C)  Increases in efficiency of food production might not be sustainable. 
D)  Input of resources required per unit of food has decreased.