Which is correct? Semi-colon or colon? One of the following statement is correct while the other one is incorrect. Which is being used properly? the semi-colon or the colon? Will give brainliest.

Choose the sentence that is not logically connected in the paragraph. (1) one final effect of radio and tv on the language must must be noted. (2) there is no doubt that these great media of information have cut down considerably the time that used to be devoted to reading. (3) radio and tv may enhance the spoken word. (4) they tend to lower comprehension levels.