Explanation:
Exp: D
A stretch of DNA consisting of 10-20 bases is most appropriately be called as oligonucleotide. DNA has double helix structure in which two strands are coiled over each other.A oligonucleotide is a short sequence of nucleotides, typically \(10-20\) bases long. Nucleotides are the building blocks of DNA and RNA, and they consist of a sugar, a phosphate group, and a nitrogenous base.