which set off an introductory phrase?
a comma
semicolon
colon
conjunction
a comma
A comma can set off an introductory phrase.
An introductory phrase is a group of words that come at the beginning of a sentence and provide additional information about the main clause. It is usually followed by a comma. Therefore, the correct answer is a comma.
Using a comma after an introductory phrase helps to separate it from the main part of the sentence, making the sentence easier to read and understand. The comma acts as a signal to the reader that the introductory phrase has ended and the main clause is about to start. This helps to avoid confusion and clarify the structure of the sentence.