This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Following required for Normal growth: 
Select and explain. 
A. Protooncogenes, B. Tumour suppressor genes, C. DNA repair genes, D. All
D: All
Answer: D: All 
Explanation: A i.e. Proto-oncogenes; B i.e. Tumor suppressorgene; C i.e. DNA repair genes