What was the primary basis for classifying organisms by humans in ancient times?

Correct answer: Their utility in human life, such as food, clothing, and shelter

Correct answer: B, usefulness to humans. Early people did not have microscopes, modern genetics, or an understanding of evolutionary relationships. They mainly grouped organisms according to visible features and their practical value in daily life. Plants and animals useful as food, sources of clothing or fibres, medicines, tools, or shelter were distinguished from harmful or less useful organisms. Option A is wrong because cellular structure requires microscopic observation and was not the main ancient basis. Option C is wrong because genes and DNA were not known. Option D is wrong because evolutionary history and common ancestry were understood much later. This early system was useful for human needs but was not a natural or evolutionary classification. Memory cue: ancient classification began with “useful or harmful?” rather than “which organism is genetically related?”