Use the Following to Answer Question

Multiple Choice

Use the following to answer question:
-(Figure: Marginal Benefits and Marginal Costs) Use Figure: Marginal Benefits and Marginal Costs.More time spent studying economics adds points to economics scores (MB) but subtracts points from accounting scores (MC) .When Claudia studies economics for four hours,the marginal benefit is _____ points;when she studies for 6 hours,the marginal benefit is _____ points.

A) 20;10
B) 30;10
C) 20;0
D) 20;30