In the above figure, the price elasticity of supply at any given quantity is
A.
highest along S 1 , next highest along S 2 , and lowest along S 3 .
B.
highest along S 3 , next highest along S 2 , and lowest along S 1 .
C.
equal to zero on each of the three supply curves.
D.
equal to one on each of the three supply curves.