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: Medicine
True about polymorphism is: 
Select and explain. 
A. Single locus --> multiple normal alleles, B. Single locus --> multiple abnormal alleles, C. Single phenotype:Single locus -+ multiple normal alleles, D. Single phenotype: Single locus --> multiple abnormal alleles
C: Single phenotype:Single locus -+ multiple normal alleles
Answer: C: Single phenotype:Single locus -+ multiple normal alleles 
Explanation: C i.e., Single phenotype, single locus, multiple normal allelle