Richard Holbrooke, who died at the age of 69 after suffering a ruptured aorta, was not the most universally beloved, but was certainly one of the ablest, the most admired and the most effective of American diplomats. He is one of the few of that profession in the past 40 years who can be compared with the giants of the "founding generation" of American hegemony, such as Dean Acheson and George Kennan.Holbrooke was tough as well as exceptionally bright. He was a loyal, liberal Democrat, but also a patriot who was prepared to be ruthless in what he saw as his nation"s interest. To his friends, he was kind and charming, but he could be abrasive: no doubt that characteristic helped prevent him becoming Secretary of State on two occasions, under Bill Clinton and again when Barack Obama became president.He held almost every other important job in the international service of the US. He was ambassador to the United Nations, where he dealt with the vexed problem of America"s debts to the organization, and to Germany. He was the only person in history to be assistant Secretary of State—the key level in routine diplomacy—in two regions of the world, Europe and Asia. He distinguished himself as an investment banker, a magazine editor, a charity executive and an author, but he will be remembered most of all for his success in negotiating an end to the war in Bosnia-Herzegovina at an Ohio airbase, and for his part in the American intervention in Kosovo. At the time of his death, he was Obama"s special representative for Afghanistan and Pakistan.Holbrooke joined the Foreign Service, and in 1963 was sent as a civilian official to Vietnam, where he was one of a talented cohort of young men who were to become leaders in American diplomacy. Once back in Washington in 1966, Holbrooke worked for two years in the White House under Johnson, and then at the State Department, where he was a junior member of the delegation to the fruitless initial peace talks with North Vietnam in Paris.By 1972, Holbrooke was ready for a change. He became the first editor of the magazineForeign Policy, created as a less stuffy competitor to the august ForeignAffairs. He also worked forNewsweekmagazine. In 1976, he went to work for Governor Jimmy Carter of Georgia, who was beginning his campaign for president and badly needed some foreign policy expertise. When Carter became president, in 1977, Holbrooke became his assistant Secretary of State for Asian affairs. Why didn"t Holbrooke become Secretary of State

A. Because he was a loyal Democrat.
Because he was strong-minded.
C. Because he was rough to his friends.
D. Because his characteristic is unique.