How Many Input Values Does the Following Code Require

Multiple Choice

How many input values does the following code require?
CREATE OR REPLACE FUNCTION memfmt1_sf
(p_id IN NUMBER,
P_first IN VARCHAR2,
P_last IN VARCHAR2)
RETURN VARCHAR2
IS
Lv_mem_txt VARCHAR2(35) ;
BEGIN
Lv_mem_txt := 'Member ' ||p_id|| ' - ' ||p_first|| ' ' ||p_last;
RETURN lv_mem_txt;
END;

A) 1
B) 2
C) 3
D) 4