In a C program, which statement regarding the main function is correct?

The statement that the main function in a C program can have zero or two parameters is accurate because the C standard defines the main function in a couple of ways. The two common signatures for the main function are int main(void) and int main(int argc, char *argv[]).

In the first case, int main(void) indicates that the function takes no parameters, while the second signature takes two parameters: argc, which counts the number of command-line arguments, and argv, which is an array of character pointers representing those arguments. This flexibility allows programmers to choose how they want their program to handle input from the command line.

The other statements do not align with C's specification of the main function. It's essential to know that the main function must always return an integer value, which typically indicates the success or failure of the program, and that it is not mandated to take parameters, nor can it return a string.