Which of the following describe understanding level teaching ?
A. Systematic, step by step presentation to promote retention of facts presented
B. Giving a large number of positive and negative examples to explain concepts
C. Insisting on effective storage of information
D. Helping to promote seeing of relationships among facts
E. Critical sifting of facts and information
Choose the correct answer from the options given below:
1. A and B only
2. B and C only
3. C and D only
4. B and D only