Which of the following is correctly punctuated?

The chosen option is correctly punctuated because it includes a comma after the introductory phrase "Due to the time-sensitive nature of the request." This comma is necessary as it helps separate the introductory clause from the main clause, making the sentence clearer and easier to read. The structure of the sentence is coherent, allowing the reader to understand that the lawyer's action of faxing the document is a direct response to the urgency implied by the introductory phrase.

In the other options, the lack of proper punctuation creates confusion. For instance, omitting the comma results in a run-on sentence, while starting a new sentence after an introductory clause or using a semicolon inappropriately disrupts the flow and clarity needed for such a statement. Thus, correct punctuation not only aids in clarity but also ensures that the relationship between the ideas within the sentence is easily understood.