Cyanobacteria, otherwise called Cyanophyta, are a phylum of microscopic organisms and plastids that acquire their vitality through photosynthesis. They are the main photosynthetic prokaryotes ready to deliver oxygen.
The name cyanobacteria originates from the shade of the microorganisms. Cyanobacteria started producing pure oxygen after the Hadean eon.
A scientific approach to explain the natural phenomenon includes various steps which begin with the making the observation. The observation made the researcher skeptical to make a scientific question which could be answered by proposing a hypothesis.
The hypothesis must be tested through experiments which could prove and disprove the hypothesis ans can answer the scientific questions.
In the given situation of the question in which a person notices or observes the fields of grass and grass and native flower. This is the first step of the scientific method called "making an observation" and thus Option-B is the correct answer.