C language Please

R.2 Write a program that will open a file named as testfile.txt". [20 Marks] A. Your program should open the file "testfile.txt" in reading and display the error if file not open. (5) B. Your program should count and display the number of uppercase characters in the file testfile.txt"(5) C. Your program should count and display the number of lowercase characters in the file "testfile.txt". () D. Write a separate piece of code that should open another file named "destinationFile.txt" in write only mode and copy contents of the testfile.txt" in it character by character. (5) Note: use character library to check whether the alphabet is lower or upper