Question: What is the first name of students enrolled in class ACCT-211 and got grade C?
SQL: SELECT T3.stu_fname FROM CLASS AS T1 JOIN enroll AS T2 ON T1.class_code  =  T2.class_code JOIN student AS T3 ON T2.stu_num  =  T3.stu_num WHERE T1.crs_code  =  'ACCT-211' AND T2.enroll_grade  =  'C'