Answer is option D. All of these choices are correct.
Explanation:
SNP or single nucleotide polymorphism is a location that showcases the difference in individual alleles by one base pair. Mainly, a genetic difference that happens between different individuals.
It is the most common variation in genetics among people. Further, every SNP represents the difference in single DNA building block known as a nucleotide. Many SNPs do not affect the health of a person. It helps in predicting a response of a person to drugs.