Grounded theory is best described as:

Grounded theory is a qualitative research methodology that is specifically designed to develop theories based on data that is systematically gathered and analyzed. The essence of grounded theory lies in its inductive approach, allowing researchers to generate new theories that emerge from the data itself rather than testing existing theories.

This methodology involves the collection of qualitative data through various means such as interviews, observations, or document analysis, followed by a coding process that identifies key themes, patterns, and insights directly from the data. The iterative process of data collection and analysis allows researchers to refine and expand their theoretical constructs continuously, making it particularly useful in fields like sociology where understanding complex social phenomena is crucial.

In contrast, focusing on existing theories, as suggested by the first option, would not align with the fundamental tenet of grounded theory. The methodology does not adhere to a purely quantitative data approach, thus ruling out any emphasis on numerical data or statistical analysis, as indicated in the third and fourth options. Grounded theory prioritizes understanding human behavior and social processes from the ground up, making option B the most accurate description.