\\\\(\ extbf{Correct Option B}\\\\) \\\\(\ extbf{Solution}\\\\)\\\\(\\bullet\\\\) Autotrophs are the organisms which are capable of manufacturing their own food with the help of photosynthesis or chemosynthesis.\\\\(\\bullet\\\\) Autotrophs are classified into two major groups namely: Photoautotrophs and chemoautotrophs. \\\\(\\bullet\\\\) Nostoc, Chara, Porphyra and Wolffia are photo synthetic autotrophs as they obtain their food through photosynthesis. \\\\(\\bullet\\\\) Nitrosomonas and nitrobacter are chemosynthetic autotrophs because they make their own food using energy from chemical reactions. \\\\(\\bullet\\\\) From the rest organisms lactobacillus, Streptomyces and saccharomyces have heterotrophic mode of nutrition. While Trypanosoma is a parasitic organism. \\\\(\\bullet\\\\) So, only six of them are autotrophs. \\\\(\\bullet\\\\) So, the correct option is B.