in C

In what order the expression below will be solved? a+b++c/d a+(((b++)(c))/d)a+((b++)((c/d)))(a+(b++))((c)/d)a+((b++)((c)/d)) Please choose the only correct observation regarding the piece of code below. switch (grade) case 'A': case 'B': case 'C': case 'D': printf("Passing"); break; case 'F": printf("Failing"); break; default: printf("Illegal grade"); \} There is nothing wrong with this code. This code is incorrect because characters cannot be used as cases in a switch. This code is incorrect because some cases are empty. This code is incorrect because there is no break for the default case