Answer: 12. C. Keep it, because it provides support for the writer’s lack of faith in global corporations.
The subordinate clause in sentence 1 provides additional evidence to support the writer's lack of faith in global corporations. It explains the reason for the writer's conclusion that there is no reason to believe that companies will change their ways in the future, even though they have failed to clean up their palm oil supply chains so far. The clause helps to build a stronger argument by providing specific details about the negative impact of the failure of these corporations on tropical rainforests.
13. B. In a landmark report, Greenpeace, the Rainforest Action Network, and Mighty Earth have revealed that four hundred companies, including the biggest brands, have broken their commitment to switch to deforestation-free palm oil by 2020.
The purpose of the added sentence is to provide factual support for the introductory claim and focus the audience on the argument of the passage. The sentence selected (B) does this effectively by presenting the results of a landmark report that highlights the failure of companies, including the biggest brands, to switch to deforestation-free palm oil. This information sets the stage for the writer's argument that the future of palm oil is grim.
14. B. The trees grow year-round and have the highest yield per acre of any oil seed, thus allowing growers to maximize land usage and produce more saleable product.
The most effective version of sentence 4 (B) explains why oil palms are "an efficient and lucrative crop" by specifying the reasons why they are so profitable. The sentence explains that the trees grow year-round and have the highest yield per acre of any oil seed, allowing growers to maximize land usage and produce more saleable product. This information provides a clear and specific explanation for why palm oil is such an efficient and lucrative crop, which supports the idea mentioned in sentence 3.