a) The United States provided supplies and military observers to France.
In the beginning, the U.S. had a neutral position regarding the Indochina war however, its position changed, as for the nation feared that the growing communism of Vietnam, would expand to other nations and result in a destabilization of powers throughout Southeast Asia and affect negatively the U.S. national security.
Therefore in 1949, the U.S. decided to support France, and by 1950, it had increased its aid toward France. It gave financial, logistical, and political assistance and military supplies. Progressively, it provided direct military assistance as well.
It is true that the Chinese were able to discover the process in producing silk about 2700 BC. So, the answer is letter A. According to the history, The silk discovered from the loss soil in Yellow River in Shanxi Province, in northern China, dated back from 2600 to 2300 or sometime near 2700 BC.
The answer is true.
Explanation is that I just learned about this topic last week and passed the test with this question on it.