please read the short scenario and help me answer the question

Assume that the local newspaper just ran the following headline and article: "Audit Results: Airport executives from Kentucky racked up $500K in lavish expenses, concert tickets, and even gentleme club tabs" LEXINGTON. Ky. (AP) - A small commercial airport in Kentucky-and the taxpayers who support itpicked up top executives' tabs in recent years for Hannah Montana concert tickets, Nintendo Wil vid game bundles and even a $4,400 gentlemen club check, according to a state auditor's report. The report released Wednesday outlines indulgences ranging from pricey electronics and exercise equipment to lavish meals and champagne. In three years, officials tallied more than $500,000 in questionable personal expenses. [Author's note: General fund expenses were approximately $10,000,000 annually.] Kentucky Auditor Crit Luallen said the former executive director at Lexington's Blue Gross Airport created a culture of wasteful spending so vast, employees sometimes were paid twice for the same expense and used airport credit cards as if they were personal checkbooks. I don't think we have ever seen an audit where so many different individuals involved in the management of a public agency abused the trust with such arrogance and lack of ethical standards," she said. Luallen says she has forwarded the case to the Kentucky attorney general, the U.S. attorney's office, and the FBI. Although the audit only covered the past three years, it does refer to one of the more glaring examples reported by the Herald-Leader. a $4,400 charge Michael Gobtrand two other directors incurred at a Dallas strip club in 2004. The charge, which appeared on the credit card statement of the airport's director of planning, was listed as going to Millennium Restaurant. The word "marketing" was handwritten next to the amount. The Associated Press obtained that receipt and others through an open records request. The audit found that airport employees also used the coffers for tuxedos and other expensive clothing: more than 400 DVDs-many of them currently missing-for the internal airport library, $14,000 in holiday hams given out as gifts; and $7,400 for a NASCAR driving experience excursion for staff described as "team building" More than 92 percent of the things Gobb charged to his airport card lacked proper documentation. Luallen said. While Luallen acknowledged that Gobb was responsible for the free-spending culture, she said the board and its public accounting firm should have supervised the airport more closely. Required: a. Discuss the role of the board of directors in monitoring the behavior of a chief executive officer. b. If the chief executive officer has subordinates incur expenses that he or she approves, how can the board prevent abuse? c. Should external auditors be expected to detect abuses such as thesens d. How should the use of credit cards be controlled