Write a Java program using ArrayList to allow the professor to enter student's names, and four test scores for each student. There should be an option to type "C" when student data entry is complete. Next, display each student's name, average score and letter grade. The output should be sorted by student last name.

Hint: Create a class or data structure hold a student first name, last name, the student's 4 test scores, and letter grade. Then create your ArrayList to hold objects of this type.