Question

Which of the following sentences is punctuated correctly?

A.
Doctors are concerned about the rising death rate from asthma, they are unsure of its cause.
B.
Doctors are concerned about the rising death rate, from asthma, they are unsure of its cause.
C.
Doctors are concerned about the rising death rate from asthma; they are unsure of its cause.
D.
Doctors are concerned about the rising death rate from asthma they are unsure of its cause.

Answer 1

The correct answer is: [C]:
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"Doctors are concerned about the rising death rate from asthma; they are unsure of its cause."
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Note:
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This correct answer— "Choice: [C]" — correctly uses the "semicolon" .
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Consider the other answer choices given:
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Choice: [A]: "Doctors are concerned about the rising death rate from asthma, they are unsure of its cause."
→ Note: This answer choice is INCORRECT. The error is using a "comma" (in lieu of a "semicolon"; or in lieu of a "period" — and then starting a new sentence". Specifically, this particular erroneous use of a "comma" is known as: "comma splice" .
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Choice: [B]: "Doctors are concerned about the rising death rate, from asthma, they are unsure of its cause."
→ Note: This use of these "commas" is incorrect. These "commas" are not only unnecessary—but "grammatically incorrect" as well—{since they confuse matters and are inappropriate by any conventional or unconventional standards whatsoever. The sentence would be correct IF the "commas" were ELIMINATED — for this particular answer choice.
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Choice: [D]: "Doctors are concerned about the rising death rate from asthma they are unsure of its cause."
→ Note: This answer choice is INCORRECT; since this particular answer is a "run-on sentence" .
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Answer 2

A is incorrect because commas are only used to separate independent clauses when they are joined by a coordinating conjunction (these are not).

B is incorrect because the commas treat the phrase "from asthma" as an appositive phrase (it is not).

C is correct; it uses a semicolon to join two independent clauses into one sentence.

D is incorrect because it is a run-on sentence.

Answer:
C. Doctors are concerned about the rising death rate from asthma; they are unsure of its cause.