C is the correct answer. All of the attempts were failed.
In April 1980, frustrated with the slow pace of diplomacy (and over the objections of several of his advisers), Carter decided to launch a risky military rescue mission known as Operation Eagle Claw. The operation was supposed to send an elite rescue team into the embassy compound. However, a severe desert sandstorm on the day of the mission caused several helicopters to malfunction, including one that veered into a large transport plane during takeoff. Eight American servicemen were killed in the accident, and Operation Eagle Claw was aborted.
President Carter continued to attempt to secure the hostages' release before his presidency's end. On 20 January 1981, minutes after Carter's term ended, the 52 US captives held in Iran were released, ending the 444-day Iran hostage crisis.
Apartheid left a huge cultural difference among the Africans. Despite being united, they were culturally aprt. This led to various civil wars.
2.Doubled is the correct answer
The existence of single-member districts discourages the creation of minor parties because the party that receives the most votes secures the office. In other words, the winner gets everything, and other parties have nothing to show for their efforts. If, by way of illustration, the Green Party fielded candidates in all 435 House races and received 20 percent of the vote in each district, it would not win any seats at all. In a system with proportional representation, seats in the legislature are allocated according to the party's share of the popular vote. Thus, minor parties are rewarded for fielding candidates in elections because their efforts result in at least a modicum of representation in the legislative branch.
2, Tet Offensive, is the correct answer to this question.
