"Which sport is held in a ring?"

Giải giúp mik với ạ!!!
   "Which sport is held in a ring?"
A. Swimming                B. Basketball                 C. Sumo, bull fighting and boxing                    D. Volleyball
   "How often are the Olympic games held?"
A. Every 4 years           B. 4 years                      C. In 2009                                                        D. Every years