Want to Assign Char Value using if condition - C Language

i am practicing to make a marks sheet where i want to assign subjects grade in a variable using if condition

here eper is subject percentage that i want to check and store it accordingly in a variable.

if(eper >=80){  
    geng = "A";
}

please do not confuse me with arrays n loops as i am in a learning phase & i am still at beginners level who has not studied Loops n arrays yet