13. The author of Passage 2 would most likely respond to the statement in the fifth sentence of Passage 1 ('Environmentalists must face the fact that unless high-yield crop varieties, pesticides, and fertilizers are widely used in developing nations, the world's food supply will be outstripped by spiraling demand') by arguing that:

Answer: C

Explanation:

High-yield crop varieties can be enhanced through limited use of agricultural chemicals.

The author would argue that agricultural chemicals can be utilized effectively on a smaller scale to significantly boost crop yields. This perspective suggests that rather than widespread reliance on these chemicals, a more measured approach can still address the challenge of feeding a growing population.

A) industrialized nations pose a greater threat to the environment than do developing nations

This option does not align with the author's argument, as the focus here is on how to enhance agricultural productivity in developing nations, rather than comparing threats posed by industrialized and developing nations.

B) many fertilizers are organic substances that produce no ill effects in humans

While this statement may hold some truth, it does not directly address the author's viewpoint regarding the efficiency and controlled use of agricultural chemicals to improve crop yields. The author emphasizes resource-conserving methods rather than merely promoting organic fertilizers.

C) agricultural chemicals can be used on a small scale and still significantly improve crop yields

This option accurately reflects the author's perspective, as they advocate for the efficient use of chemicals rather than widespread application. The author believes that high yields can be achieved through a careful and limited use of agricultural chemicals, aligning with their emphasis on sustainable practices.

D) the use of pesticides is unnecessary if high-yield crop varieties are adopted

This option misrepresents the author's stance. The author does not claim that high-yield crop varieties eliminate the need for pesticides; rather, they argue for an efficient and sensible use of chemicals to support agricultural productivity while also considering environmental impacts.

Conclusion

The correct answer is C, as it encapsulates the author's argument for the targeted use of agricultural chemicals to enhance crop yields without resorting to extensive application that can harm the environment. Other options either misinterpret the author's position or stray from the focus on improving agricultural practices in a sustainable manner. Thus, C is the only option that aligns with the call for a balanced approach to agricultural productivity.