Susan wishes to buy gasoline and have her car washed. she finds that if she buys 9 gallons of gasoline at $2 per gallon, the car wash costs $1.50,but if she buys 10 gallons of gasoline, the car wash is free. for susan, the marginal cost of the tenth gallon of gasoline is:
a. 50 cents.
b. $1.
c. zero.
d. $1.50.

Christopher kim, cfa, is a banker with batts brothers, an investment banking firm. kim follows the energy industry and has frequent contact with industry executives. kim is contacted by the ceo of a large oil and gas corporation who wants batts brothers to underwrite a secondary offering of the company's stock. the ceo offers kim the opportunity to fly on his private jet to his ranch in texas for an exotic game hunting expedition if kim's firm can complete the underwriting within 90 days. according to cfa institute standards of conduct, kim: a) may accept the offer as long as he discloses the offer to batts brothers.b) may not accept the offer because it is considered lavish entertainment.c) must obtain written consent from batts brothers before accepting the offer.