​Which of the following is an example of a "metering" strategy

A) ​A supermarket offers free parking space but charges higher for grocery
B) A television reseller spends time making sure that the picture quality of the bargain priced sets is fuzzy
C) Razors are sold at unit cost while razor blades have large profit margins
D) ​All of the above

Refer to Figure 5-21. Using the midpoint method, what is the price elasticity of supply between $25 and $35?