As part of its policy of "containment" during the cold war, the united states hoped to keep communist influence in korea
a. south of the yalu river. eliminate
b. south of the mekong delta.
c. north of the 38th parallel.
d. north of the 17th parallel.

The answer is c. north of the 38th parallel. President Truman told MacArthur to keep the conflict within the 38th parallel.  However when they push the North Koreans out of the South, they crossed over this boundary.  This caused the Chinese to launch an attack that further complicated the war.

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.