Question

read the sentence.
conservationists are considering urban runoff and they are tracking population growth but the magnitude of
the situation has not been determined.

according to the elements of style, what is the correct way to punctuate this sentence?

conservationists are considering urban runoff and they are tracking population growth, but the magnitude of the
situation has not been determined.

conservationists are considering urban runoff, and they are tracking population growth but, the magnitude of the
situation has not been determined.

conservationists are considering urban runoff, and they are tracking population growth, but the magnitude of the
situation has not been determined.

no change

Explanation:

To determine the correct punctuation, we analyze the sentence structure. The sentence has two independent clauses joined by "and" and "but". When joining independent clauses with a coordinating conjunction (and, but, etc.), a comma should precede the conjunction.

• The first option: Missing a comma before "and" (between "runoff" and "and").
• The second option: Incorrect comma placement before "but" (should be before "but" to separate the independent clause, not after).
• The third option: Correctly places commas before "and" (separating "runoff" and the next clause) and before "but" (separating the second clause and the third clause), as per the rules of coordinating conjunctions with independent clauses.
• The "no change" option is incorrect because the original sentence lacks necessary commas.

Answer:

C. Conservationists are considering urban runoff, and they are tracking population growth, but the magnitude of the situation has not been determined.