Hooterville Has Seen Its Population Grow by 200% Over the Past

Hooterville has seen its population grow by 200% over the past decade (10 years) . Urban sprawl has occurred as city services have been extended to formerly rural areas. Mark'sManhole Cover Company, Inc. has seen sales to the City of Hooterville triple during this period. This is most likely due to

A) increased manhole cover prices
B) increased quantity supplied of manhole covers
C) altered consumer expectations
D) increased demand for manhole covers
E) increased supply for manhole covers