单项选择题



*All references to homes in the data and test questions should be interpreted as one—family homes.
Note:Graphs drawn to scale.

For which of the following years was there an increase over the previous year in the number of existing homes sold,but a decrease in the number of new homes sold()

A. 1972
B. 1973
C. 1974
D. 1977
E. 1979