Write a C program that assigns test score grades. The program's input should be a series of test scores of type int. Have the program read each score and print either the corresponding grade or an appropriate error message. The program is to continue until end-of-file. Assume the following grading scale: 9 - 10 A 8 B 7 C 6 D 0 - 5 F Use a switch statement to assign or print the appropriate grade.