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Sentence Correction: Pronoun Questions - Ambiguity

A great cause of concern among public health specialists is the preponderance of dioxins and polychlorinated biphenols in the food chain, increasing the risk of bio-accumulation of these toxins in fatty tissue and to result in elevated risk of developing sarcomas.

Incorrect.

This answer choice is grammatically incorrect. The construction A and B (increasing and to result) requires that A and B belong to the same part of speech. In this case, A (increasing) is a non-conjugated verb of the V+ing form, whereas B (to result) is a non-conjugated verb of the to V form.

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This answer choice is grammatically incorrect. The construction A and B (increased and resulting) requires that A and B belong to the same part of speech. In this case, A (increased) is an adjective, whereas B (resulting) is a non-conjugated verb.

Incorrect.

While this answer choice corrects the Parallelism mistake in the original question, it introduces a new grammatical mistake. By changing to result (the second item in the parallelism) to which results, this answer choices turns the last part of the sentence into a relative clause which modifies the clause immediately before it, and corrects the faulty parallelism of the original sentence (increasing and to result).

However, by changing these toxins to their, the corrected sentence creates a Pronoun Ambiguity error. The pronoun their could refer to any of the plural nouns in the preceding part of the sentence: specialists, dioxins, or biphenols.

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Well done!

This answer choice corrects the Parallelism mistake in the original question by changing to result to resulting.  The parallel construction increasing the risk...and resulting in elevated risk modifies the noun phrase preponderance of dioxins and polychlorinated biphenols in the food chain.

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Incorrect.

This answer choices is grammatically incorrect, illogical and changes the meaning of the original sentence.

The corrected sentence creates a parallel list of three items that are neither grammatically nor logically parallel:

A great cause of concern is...a preponderance (noun)..., to increase (verb)...and to result (verb).

In addition, the corrected sentence is illogical, as it makes no sense to say that the health specialist's concern is to increase the risk. Their concern is to reduce risk.

What helps us identify this question as a Parallelism question as well as identify the mistake is the following Stop Sign:

A list of 3 items or more, separated by commas and and/or before the last item.

When you identify this structure, make sure it follows these rules: All items in the list must be of the same part of speech, and must be logically parallel.

increasing the risk of bio-accumulation of these toxins in fatty tissue and to result
with increased risk of bio-accumulation of these toxins in fatty tissue and resulting
and their increased bio-accumulation in fatty tissue, which results
increasing the risk of bio-accumulation of these toxins in fatty tissues and resulting
to increase the risk of their bio-accumulation in fatty tissue and to result