The "Dynamic Pricing" Model Used by the Ride-Sharing Firm Uber

Multiple Choice

The "dynamic pricing" model used by the ride-sharing firm Uber, along with a few other firms, illustrates which of the following?

A) When there is shortage in a market, the equilibrium price will rise.
B) Once the equilibrium price is reached, it will remain there for at least several days.
C) Since actual quantity bought always equals actual quantity sold, the market is always at equilibrium.
D) When there is surplus in a market, the equilibrium price will rise.