Please i need some help with my programing assigment in Java

Which one of the following fragments shows the most appropriate way to throw an exception? Assume that any undeclared variables have been appropriately declared elsewhere and are in scope and have meaningful values. Exception e = new IO Exception("File not found"); if (!f. exists O) {//f is a File object throw e;} if C !f. exists()) {//f is a File object throw new I0Exception("File " + f. getName() + not _ found"); if (!f. exists()) {throw IO Exception; if (!f. exists()) {throw "File not found"; if (!f. exists O) {//f is a File object throw new I0Exception()