Recall the Application About the Behavior of Prices in Retail

Recall the Application about the behavior of prices in retail catalogs to answer the following question(s) .
Economist Anil Kashyap of the University of Chicago examined the prices of 12 selected goods from L.L.
Bean, REI, and The Orvis Company, Inc. Kashyap tracked the prices from the companiesʹ catalogs which
were reissued every six months.
-According to this Application, the prices which were tracked in the retail catalogs exemplified the macroeconomic concept of the short run, a period of time in which

A) price changes are significant because the aggregate supply curve is vertical.
B) prices never change because the aggregate demand curve is vertical.
C) prices change frequently because of changes in aggregate supply.
D) prices donʹt change very much, implying that aggregate supply is relatively flat.