Global dimming is most apparent over urban regions or in the mid-latitudes of the Northern Hemisphere where a. the use of air conditioners and refrigerators is the greatest
b. the Arctic and Greenland glaciers are melting at a very fast rate
c. the human population is greatest
d. prevailing winds circle the earth
e. jet air traffic is more common

c

Explanation: i took the test

The vestigial came about from the common descent and evolutionary theory. Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time. 

Over the period of millions of years, animals have went through many changes and the vestigial structures are forming. Even humans have about 6 vestigial structures..