While the sales of the Apple iPhone have been great from the beginning, when Apple released its iPhone 4S and cut the price of the iPhone 4 from $399 to $199, sales exploded with one million iPhone 4 models sold the first weekend. Demand for the iPhone appears to be:
a. unitary.
b. predictable.
c. synergistic.
d. inelastic.
e. elastic.
ANSWER: e