Write code in C

3. Please answer the questions regarding strings. a. Declare a string named S1 and take input from users. Count the string length. [5] b. Copy S1 into a new string named S2. [10] C. Replace all the vowels of S2 using '*' and place it in 53. [10] [ d. Copy the contents of S1 in backwards in S4. For example if S1 had harere", 54 should have "ererah". [10]