Which of the following are the 5 characteristics of​ objectives? A. ​quantitative, understandable,​ challenging, compatible, qualitative B. ​qualitative, understandable,​ challenging, compatible, obtainable C. ​quantitative, understandable,​ challenging, compatible, obtainable D. ​quantitative, understandable,​ realistic, compatible, obtainable E. ​quantitative, understandable,​ challenging, clear, obtainable