8. Variation on 13.4#7). Express each of these sets using a regular expression. (a) the set of strings of three or more Os followed by a1.[5 points Replace this text with your answer. (b) the set of strings of two or more symbols followed by five or more 0s. 5 points] Replace this text with your answer. (c) the set of strings with either no 1 following a 0, or no 0 following a 1 5 points] Replace this text with your