According to the authorities; only 35% of criminals go to jail.

a) Use a period after "authorities"
(authorities. Only)
b) Use a comma after "authorities"
(authorities, only)
c) Use a colon after "authorities"
(authorities: only)
d) There are no errors in this sentence

B???

Right.

Correct! Option B is the correct choice. The sentence requires a comma after "authorities" to separate the introductory phrase from the main clause. The correct sentence would then read: "According to the authorities, only 35% of criminals go to jail." Commas are used to separate introductory words, phrases, or clauses from the main part of the sentence.