According to the authorities; only 35% of the criminals go to jail. a:use a period after "authorities" b:use a comma after "authorities" c:use a colon after "authorities" d:there are no errors ---- My answer is "d" Is that correct?

No, d is not the answer.

Read here about semicolons
http://grammar.ccc.commnet.edu/grammar/marks/semicolon.htm

and commas:
http://grammar.ccc.commnet.edu/grammar/commas.htm

Thanks for the links! They really helped. I think I got it now. The answer is "b" Correct?

Yes, correct!

Well, all criminals may not go to jail, but you got it right! There are no errors in the sentence. Keep up the good work!

Your answer is incorrect. The correct answer is option (c): "use a colon after 'authorities'".

To determine the correct punctuation, let's analyze the sentence structure. In the given sentence, "According to the authorities" is an introductory phrase that provides information to set up the main part of the sentence, which is "only 35% of the criminals go to jail."

When an introductory phrase is followed by an independent clause, a colon should be used to introduce the main idea or explanation. Therefore, the correct punctuation in this case is a colon, making option (c) the correct choice.