char with basic if solution to school

I am just stuck and can not find the solution...

what is wrong, it only shows the letter A and when you type B or C is the same.

char A, B, C;

A = 'A';

B = 'B';

C = 'C';

printf("Enter grade:  ");
//scanf_s( " %c",grade,1);
scanf_s(" %c", &A, &B, &C,1);



if ('A') {
    printf("The increment is = %f\n ", (salary * 2.5) / 100);
}
else if ('B') { 
    printf("The increment is = %f\n ", (salary * 1.5) / 100);
}
else {
    printf_s("The increment is = %f\n", (salary * 0.0) / 100);
}
printf("Increment and Tax for over years years");

thank you.