Which of the following ' C ' functions is precise to verify the emptiness of a Queue?

• A. int empty(Q*P){ if (P->R==-1)return (1);return(0);}
• B. int full (Q*P){if(P->R==MAX-1)return(1);return(0);}
• C. int empty (Q*P){if (Preturn(0);return(1);}
• D. int full (Q*P){if(Preturn(0);return(1);}