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[ Option A ]

In C file handling, every open file is associated with a file pointer that indicates the current position for reading or writing within the file. As operations like fread(), fwrite(), and fgets() are performed, this pointer automatically moves forward, tracking the progress through the file.
The rewind() function is used to reset this file pointer back to the beginning of the file (byte 0). It allows the program to read or process the file again from the start without closing and reopening it, making file operations more efficient and convenient.
The rewind() function also clears any error or EOF (End Of File) flags associated with the file.

[ Option C ]

In C, the feof() function is used to check whether the End of File (EOF) has been reached for a file stream. It returns a non-zero value if EOF is reached, otherwise it returns zero.
The condition if(!feof(infile)) checks whether the end of the file has not been reached. The function feof(infile) returns a non-zero value when the end of file is reached, so using the logical NOT operator (!) means the condition becomes true when the file has not yet reached its end, and therefore the message is printed.

[ Option B ]

In C file handling, both fseek() and rewind() functions are used to move the file pointer, but they differ in flexibility and feedback. 
The fseek() allows moving the file pointer to any desired position and also returns a value or status indicating whether the operation was successful or not. It returns 0 on success.
The rewind() simply moves the file pointer to the beginning of the file and does not return any value, so it provides no status about success or failure.

[ Option C ]

In C language, fscanf() is used to read formatted input from a file. It works similarly to scanf(), but instead of reading from standard input i.e., keyboard, it reads from a file.
Syntax:
fscanf(FILE *fp, const char *format, variable_list);
The first argument is a file pointer (FILE *fp), which specifies from which file data should be read.
The second argument is the format string, which defines the type and format of data to be read like %c, %d, %f, %s, etc.
After that, variables are passed where the read values will be stored.
#include <stdio.h>
int main() 
{
    FILE *fp;
    int id;
    char name[20];
    fp = fopen("myfile.txt", "r");
    fscanf(fp, "%d %s", &id, name);
    printf("Rollno : %d, Name : %s", id, name);
    fclose(fp);
    return 0;
}

[ Option D ]

In C, getc() reads one character from a file and returns the character value if a character was read, or the special macro EOF if the end of file is reached or an error occurs.
So, to check whether the end of the file has been reached when using getc(), we compare its return value with EOF, not with any function call.
In the given code int c = getc(infile); reads a character, and the condition if(c != xxxx) should check whether the character is not equal to EOF, meaning the file has not ended yet.

[ Option A ]

File modes control the type of access you have to a file. When a file is opened in the mode <r>, it means the file is opened for reading only. In this mode, you can only view or read the contents of the file, but you cannot make any changes like writing, deleting, or overwriting the file.