Correct option (b) Escherichia
Explanation:
The kingdom-Monera (Gr. monera = simple) includes simple, prokaryotic primitive organisms. It includes bacteria, archaebacteria, Actinomycetes, Mycoplasma, spirochetes. rickettsiae, chlamydiae and cyanobacteria. Escherichia call is the most studied bacterium. E. coli is an enteric bacteria, found in the entire colon, secretes vitamin-B3, B6, B12 and folic acid.
