Use the model shown to answer this question. The model represents the database used by a veterinary office. The office tracks pets, owners, office visits with treatments, and doctors. Which entities in the following model are 'Strong' entities? Pet Doctor doc_fname doc_lname doc_officeNum HI-- 04 treated by pet_tagNum pet_name pet_DOB pet_type treats + 1 has 1 1 1 1 assigned to 1 1 1 1 1 1 1 owned by 1 1 1 1 1 _is for assigned te es Appointment appt_date appt_time pet_tagNum appt_exam Room owns 1 includes Owner own_fname own_Iname own_addr own_city own_state own_zip Code included in Treatment treatment_type treatment_option All entities are Strong No entities are Strong Doctor and Owner are strong entities Treatment is Strong. O Pet and Owner are Strong