Medications taken for the treatment of
a. can be easily purchased at any store
b. begin to reduce depression immediately
c. must be monitored closely for the proper dosage
d. usually have no side effects

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.