(a) Write a C program to print a list of all integers between 1 and 1,000 (inclusive) which are divisible by 7 but not by 13. The list should be printed to a file called "output.dat". Remember to close the file after use. (35%) (b) Explain what is meant by the C preprocessor. Explain the effect of the following line of code: #define SQUARE (x) (x) * (x) (25%) (c) Explain the concept of an array in C. Write down the C code to: (i) declare an array called ivec consisting of 10 integers; (ii) dynamically allocate memory for an array called fvec consisting of n floating-point numbers, where the value of n is input at the keyboard; (iii) set the first element of fvec to be equal to 2.7; (iv) assign values to the remaining elements of fvec so that every such element is equal to the cube of the previous element; (v) print the final element of fvec to the screen, using 2 decimal places. Explain clearly the difference between an array and a character string. (40%)