The correct option is B Monera
The five kingdom classification was proposed by R. H. Whittaker in the year 1969. The kingdom Monera is comprised of unicellular prokaryotic organisms. This group contains the bacteria and the cyanobacteria species. These are the prokaryotic organisms which do not have well-developed cell organelles like the nucleus, mitochondria, and chloroplast. The other four kingdoms, protista, fungi, plantae and animalia are composed of all the eukaryotic organisms. Thus, the correct answer is option A.