The Truman doctrine and the containment policy were designed to what?​

The Truman doctrine and the containment policy were designed to what?​“stop communism”.

Explanation:

The Truman Doctrine was announced in the Congress by President Truman on March 1947 and was designed as a foreign policy in order to avoid the expansion of the Soviet Union and Communism in the world. According to this policy, US provided financial and military support to those countries that were threatened by communism; in this case Turkey and Greece.  

a historian researching the immigration policies of the early 1900s would expect a source written today,rather than in 1910 to :

( a ) be more interested in objective data and statistics.