Write a C program that includes the following:

1. (7 points) A function called CheckTelephone, which receives a string as an input, and checks whether it is a correct telephone number or not.

Note: For a string to be a correct telephone number it should be 7 characters long and contains no alphabets.

2. (6 points) The main function, which lets the user input a string, then the main calls the function CheckTelephone to check if it is correct or not, if yes , the main should verify the operator of the number as follows:

• The number starts with 078: display "Umniah operator".
• The number starts with 079: display "Zain operator".
• The number starts with 077: display "Orange operator".