Explanation:
Given the importance of oxygen for animals, researchers suspected that a sudden increase in the gas to near-modern levels in the ocean could have spurred the Cambrian explosion. ... This supported the idea of oxygen as a key trigger for the evolutionary explosion.
MacArthur was opposed to Truman's policy of containment in Korea. So its True.
I think the correct answer from the choices listed above is option D. The type of dispersal that occurs due to global trade would be jump. <span>Jump-dispersal is the movement of individual organisms across great distances, followed by the successful establishment of a population.</span>
