a) Write a function to calculate standard deviation of the pointer input argument. b) Write a function to sort pointer argument in descending order based on the remainder of three and print them. ( for the input {9,7,1,5) after sorting {5,1,7,9}) c) Write a complete C program to calculate the standard deviation and sort the data inside the array using the functions defined above. The program will ask to the user to enter the size of the array and then will take the numbers to the array using scanf for the entered size. After creating the array, call the functions defined in a) and b) and give the array to the functions as an input 1 Standard Deviation: s= VN- 1-1([i] mean)2 Note: Use pointer definition for the functions. The array definition inside the functions will be not accepted