Which correctly defends the author's use of a colon in the following sentence? i've decided not to try out for varsity football next year: the new coach expects all players to attend a four-week summer camp! a) the colon is used to introduce an elaboration of the main clause. b) the colon is used in place of a hyphen for the compound modifiers. c) the colon is used to indicate an elaboration of the dependent clause. d) the colon is used at the end of a heading which introduces a new section of a document.