Write a function that evaluates the following series up to nth term and returns the output: 1*2 2 * 3 3*4 + + + 3! 4! 5! Note: Here 1st term is (1*2)/3! , 2nd term is (2*3)/4! and it will go this way up to the nth term. Your function will take input n and return the summation of the series. Write the necessary code to call your function in the main function. a. Provide the C program in your answer script. Provide explanations in your code as comments. b. Show output screenshot when the user will input n=5