During the presidency of Richard Nixon, the United States

a) sought to protect human rights.
b) sought to close the USSR out of world markets.
c) retreated into relative isolation.
d) worked for a reduction of tensions known as detente.
e) none of the above

b, c are dead wrong. d is generally right. http://www.americanforeignrelations.com/E-N/Human-Rights-The-kennedy-johnson-nixon-and-ford-presidencies.html

To determine the correct answer, let's examine the options one by one:

a) During Richard Nixon's presidency, the United States did take some steps towards protecting human rights. However, this was not the primary focus of his administration, so option a) may not be the correct answer.

b) The United States did engage in efforts to contain the influence of the USSR during the Cold War, but seeking to close the USSR out of world markets wasn't a central objective of Nixon's presidency. Therefore, option b) may not be the correct answer.

c) Nixon's presidency did not involve a retreat into relative isolation. In fact, he pursued a policy of engaging with various countries, including China and the USSR. Therefore, option c) is unlikely to be the correct answer.

d) The correct answer is d) worked for a reduction of tensions known as détente. Richard Nixon's administration aimed to improve relations with the Soviet Union and China. One notable achievement of this policy was the Strategic Arms Limitation Talks (SALT), which aimed to reduce nuclear arms and ease tensions between the superpowers.

e) Since options a), b), and c) are not accurate, and option d) aligns with Nixon's foreign policy goals, the correct answer is e) none of the above.

In conclusion, during Richard Nixon's presidency, the United States primarily worked for a reduction of tensions with the USSR, known as détente, which is represented by option d).