Among the following options, which would be consistent with an unexpected fall in the price level, according to theSticky-price Theory?

Select one:

a.Some firms' prices are lower than desired, which depresses their sales.

b.Some firms' prices are lower than desired, which increases their sales.

c.Some firms' prices are higher than desired, which increases their sales.

d.Some firms' prices are higher than desired, which depresses their sales.