Which of the Following Best Describes the Series of Events

Multiple Choice

Which of the following best describes the series of events shown in the figure? The original conditions prior to the change are shown by D ₀ and S ₀ (point A) , and S _LR is the market long-run supply curve.

A) an increase in demand and an expansion in the number of firms in an increasing cost industry
B) an increase in demand and an expansion in the number of firms in a decreasing cost industry
C) an increase in demand and an expansion in the number of firms in a constant cost industry
D) none of the above