28. (Refer to code above.) How many columns will the result set have? a. 4 b. 5 c. 6 d. 7 29 When you crea tea PDO object, you have to pass all but one of these arguments to it: Which one is it? a. Data source name b. Server name c. User name d. Password 30. Which of the following is the correct way to code a PHP statement that returns the result set for a SELECT statement that's stored in Sstatement if the PDO object is db? a. b. c. d. *re sults $re sults *results $re sults = = = = $db->query ($statement); $db->exec($statement); query->$db ($sta tement) ; exe c-db($ statement)