The correct answer is A. The captain said, "But he needn't come round when you are on watch, Mr. Brown."
Explanation
There are many rules for correct writing. One of them states that when quotation marks are used, the period at the end of the sentence must be placed within quotation marks. On the other hand, another grammar rule states that when an introductory sentence is given, it must be separated from the quotation by a comma. According to the above rules, the correct answer is A. because the introductory part "The captain said" is separated from the second part of the sentence using a comma. Also, the second part of the sentence that is between the quotation marks, places the final period within the quotation marks. So the correct answer is A. The captain said, "But he needn't come round when you are on watch, Mr. Brown."
