This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
A codon consists of: 
Select and explain. 
A. One molecule of aminoacyl-tRNA, B. Two complementary base pairs, C. Three consecutive nucleotide units, D. Four individual nucleotides
C: Three consecutive nucleotide units
Answer: C: Three consecutive nucleotide units 
Explanation: Ans. C. Three consecutive nucleotide units(Ref: Harper 31/e page 399)Each codon consists of a sequence of three nucleotides, i.e. it is a triplet code.