Write an iterative C function that inputs a nonnegative integer n and returns the nth Fibonacci number. 2. Write a recursive C function that inputs a nonnegative integer n and returns the nth Fibonacci number. 3. Compare the number of operations and time taken to compute Fibonacci numbers recursively versus that needed to compute them iteratively. 4. Use the above functions to write a C program for solving each of the following computational problems. I. Find the exact value of f100, f500, and f1000, where fn is the nth Fibonacci number. What are times taken to find out the exact values