Cost-volume profit is used to analyze  

a. the behaviour of variable costs at all levels of output.

b. multiple revenue drivers and a single cost driver in special case CVP.

c. a single revenue driver and multiple cost drivers in special case CVP.  

d. the behaviour of total costs, total revenues, and operating income as changes occur in the output level.  

e. the behaviour of some costs and revenues as changes occur in the output level.