Around the World in 80 Questions (Day 10): Contrary to earlier

Experts' Global Official Explanation:

Meaning + Verb Forms + Modifiers + Redundancy/Awkwardness

Understanding the intended meaning is key to solving this question; the intended meaning of the crucial part of this sentence is that the “increase in water pollution” that occurred due to the dumping of iron may hasten global warming by poisoning phytoplankton.

A. Trap. This answer choice alters the meaning of the sentence through the phrase “as a result of dumping”; the construction of this phrase illogically implies that because of the dumping of iron, “increased water pollution” may hasten global warming by poisoning phytoplankton; the intended meaning of the sentence is that the “increase in water pollution” that occurred due to the dumping of iron may hasten global warming by poisoning phytoplankton.

B. Trap. This answer choice alters the meaning of the sentence because of the usage “increasing pollution”; the use of the present participle (“verb+ing” – “increasing” in this sentence) incorrectly implies that the ongoing action of increasing water pollution may hasten global warming by poisoning phytoplankton; the intended meaning of the sentence is that the increase in water pollution that has already occurred due to the dumping of iron may hasten global warming by poisoning phytoplankton; remember, present participle (“verb+ing” – “increasing” in this sentence) noun modifiers refer to ongoing actions. Additionally, the phrase “pollution in the water” is needlessly wordy, leading to awkwardness in Option B.

C. Correct. This answer choice correctly uses the past participle “increased” and the present participle (“verb+ing – “resulting” in this sentence) phrase “resulting from the dumping of iron” to modify “water pollution”, conveying the intended meaning of the sentence- that the increase in water pollution that has already occurred due to the dumping of iron may hasten global warming by poisoning phytoplankton. Further, Option C is free of awkwardness and redundancy.

D. This answer choice alters the meaning of the sentence through the phrase “pollution in the water that increase”; the construction of this phrase incorrectly implies that the pollution itself may hasten global warming by poisoning phytoplankton; the intended meaning of the sentence is that the “increase in water pollution” that occurred due to the dumping of iron may hasten global warming by poisoning phytoplankton. Further, Option D incorrectly uses the plural verb “increase” to refer to the singular noun “pollution”. Additionally, the phrase “pollution in the water” is needlessly wordy, leading to awkwardness in Option D.

E. Trap. This answer choice alters the meaning of the sentence through the phrase “water pollution that increased”; the construction of this phrase incorrectly implies that the pollution itself may hasten global warming by poisoning phytoplankton; the intended meaning of the sentence is that the “increase in water pollution” that occurred due to the dumping of iron may hasten global warming by poisoning phytoplankton.

C is the best answer choice.