public QuestionService(
     IQuestionRepository questionRepository, 
     IAnswerChoiceRepository answerChoiceRepository,
     IExamRepository examRepository
     )
 {
     this.questionRepository = questionRepository;
     this.answerChoiceRepository = answerChoiceRepository;
     this.examRepository = examRepository;
 }
 public AnswerChoicesController(IAnswerChoiceRepository answerChoiceRepository)
 {
     this.answerChoiceRepository = answerChoiceRepository;
 }
 public AnswerChoiceService(IAnswerChoiceRepository answerChoiceRepository)
 {
     this.answerChoiceRepository = answerChoiceRepository;
 }