下面声明一个名为cursor_student的游标,语法格式正确的是()。
A.CURSOR cursor_student OF select s_name,s_gender FROM student;
B.CURSOR cursor_student FOR select s_name,s_gender FROM student;
C.DECLARE cursor_student CURSOR FOR select s_name,s_gender FROM student;
D.DECLARE cursor_student CURSOR OF select s_name,s_gender FROM student;