When it comes to punctuation, you will use commas and periods most frequently. A good writer, however, needs to know how to use colons and semicolons as well. These two punctuation marks might look similar, but they serve different purposes. Determine which punctuation rule is illustrated by the following sentence. "I have never met someone who does his job so well; he is consistently professional."

a. Use a colon after a complete thought that introduces a list of items.
b. Use a colon to join closely related independent clauses.
c. Use a semicolon after a complete thought that introduces a list of items.