In most prokaryotes, the chromosome number is :

Prokaryotes, which include bacteria and archaea, are unicellular organisms characterized by the absence of a membrane-bound nucleus and other membrane-bound organelles. In the vast majority of prokaryotes, the genetic material is organized into a single, circular chromosome consisting of double-stranded DNA.

Unlike eukaryotes, which possess multiple linear chromosomes housed within a nucleus, the prokaryotic chromosome is located in an irregularly shaped region of the cytoplasm called the nucleoid. While some specific species (such as Vibrio cholerae) may possess more than one chromosome, the standard biological classification for most prokaryotes identifies the chromosome number as 1 (Option D). This single chromosome contains the essential genetic information required for the organism's growth, survival, and reproduction.