Write a C program that will get 10 grades of the student from a file named grades.txt. The program will check each grade if its passing, failing or invalid. Passing grade is XXXXXXXXXXFailing grade is...

Write a C program that will get 10 grades of the student from a file named grades.txt. The program will check each grade if its passing, failing or invalid. Passing grade is 70-100. Failing grade is 0-69. Other value will be considered invalid. Store all the passing grade to an output file named passed.txt. Store all the failing grades to an output file named failed.txt. And store all the invalid grades to another output file named invalid.txt. The program must comply with the given sample output below:

Please help!, how to fix my code?

My code!

#include
#include

//MAIN METHOD
int main()
{
//Declare file pointers
FILE *fin,*fpass,*ffail,*finvalid;
//Declare variablef to store filename
char str[30];
//Declare variables: option and ch
int option,ch;

//Read file name
printf("Enter File Name: ");
scanf("%s",str);


//Open input file in read mode.
fin = fopen(str,"r");
//Open Output file in write mode.
fpass= fopen("passed.txt","w");
ffail = fopen("failed.txt","w");
finvalid = fopen("invalid.txt","w");

//Display error message if input file is not opened.
if(fin == NULL)
{
printf("Error in opening %s!",str);

exit(1);

}

//Read first integer from input file
fscanf(fin,"%d",&ch);
//Use While loop, to read all integers from file and place them in respective output files.
while (!feof(fin))
{
//if integer is with in 70-100 then put them in passed.txt file.
if(ch<=100 &&="" ch="">=70)
{
fprintf(fpass,"%d\n",ch);
}
//If integer is with in 0-69 then put them in failed.txt file.
else if(ch<70 &&="" ch="">=0)
{
fprintf(ffail,"%d\n",ch);
}
//otherwise put the integer in invalid.txt file
else{
fprintf(finvalid,"%d\n",ch);
}
//read next integer from file
fscanf(fin,"%d",&ch);
}

printf("\nAll grades are evaluated and stored in their respective files.");
//Close all file pointers
fclose(fpass);
fclose(ffail);
fclose(finvalid);

//Display File menu
printf("\nDISPLAY FILE MENU");
printf("\n[1] Passing\n[2] Failing\n[3] Invalid\nOption:\nPassing Grades: ");
//Read option from user
scanf("%d",&option);
//Use switch, to display respective file content based on user choice
switch(option)
{
case 1:

//If case-1, Display passed.txt file information.
//Open file in read mode
fpass= fopen("passed.txt","r");
//Use while loop, to display all integers in passed.txt file.
fscanf(fpass,"%d",&ch);
while (!feof(fpass))
{
printf("%d, ",ch);
fscanf(fpass,"%d",&ch);
}
break;
case 2:

//If case-2, Display failed.txt file information.
//Open file in read mode
ffail = fopen("failed.txt","r");
//Use while loop, to display all integers in failed.txt file.
fscanf(ffail,"%d",&ch);
while (!feof(ffail))
{
printf("%d, ",ch);
fscanf(ffail,"%d",&ch);
}
break;

case 3:

//If case-3, Display invalid.txt file information.
//Open file in read mode
finvalid = fopen("invalid.txt","r");
//Use while loop, to display all integers in invalid.txt file.
fscanf(finvalid,"%d",&ch);
while (!feof(finvalid))
{
printf("%d, ",ch);
fscanf(finvalid,"%d",&ch);
}
break;

default:
printf("Invalid Option");


}

}