Question 1 What is the difference between the regular expressions abc and abc+? The first can match the empty set, the second cannot The first can match any order of a's, b's and c's, the second requires that the letters be in order The first does not require any instances of either a, b or c as long as there is at least one letter while the second requires at least one of each The first does not require any c's, the second requires at least one c There are no differences O O O O Question 2 Using :punct, provide a regular expression which will match any string that contains at least one punctuation mark. Question 3 Which of the following best describes the regular expression IA+$(there is a blank space after the second A)? O Any string that contains at least one blank space Any string that starts with at least one blank space Any string that consists solely of blank spaces Any string that contains no blank spaces Any string that contains only A (caret symbols) and blank spaces O O O O Question 4 Using [0-9], provide a regular expression to match a dollar amount that will be of the form $digits.digits where the digits after the decimal point must be exactly two digits