Task: Question Generation
Input (English): Passage: At the start of September 1964, General Lâm Văn Phát was dismissed as Interior Minister, while General Dương Văn Đức was about to be removed as IV Corps commander. Both were removed partly due to pressure from Buddhist activists, who accused Khánh of accommodating too many Catholic Diệm supporters in leadership positions. Diệm had tried to use the loyalist Phát to help thwart the November 1963 coup, but the rebels managed to sideline Diệm's general and execute the president. Disgruntled by their demotions, Phát and Đức launched a coup attempt before dawn on September 13, having recruited ten army battalions. They gained the support of Colonel Lý Tòng Bá, the head of the 7th Division's armored section, and Colonel Dương Hiếu Nghĩa, a tank commander who had been one of Diệm's assassins. It appeared at this stage that the coup was supported by Catholic and Đại Việt elements. Another member of the conspiracy was Colonel Phạm Ngọc Thảo, who while a Catholic, was a communist spy trying to maximize infighting at every possible opportunity.Đức and Phát's plot was supported during the planning phase by Defense Minister and triumvirate member Khiêm. General Huỳnh Văn Cao, a Catholic and Diệm loyalist while the former president was alive, claimed in a 1972 newspaper interview that Khiêm—by then prime minister—had asked him to join the coup. Cao said he had declined Khiêm's invitation, mildly mocking him by asking "You're part of the 'Troika' now ... won't you be overthrowing yourself?" Cao said he had pointed out that political upheaval in Saigon would be a bad idea because Vietnam was prominent during the ongoing US presidential election campaign and negative publicity could lead to a decrease in American public and political support for South Vietnam.
Output (English): What was the full name of the person who declined Khiêm's invitation?