The correct answer is B) by developing words for tools that were unique within their communities.
According to one major language theory, different groups developed their own languages by developing words for tools that were unique within their communities.
Scientists do not agree on a single source as the origin of human language. However, some scientists agree on the idea that aa group of nomads that wandered Western Asia and Eastern Europe in 3000 BC, could be the ones who formed a series of sounds that represented a primitive first form of language. That language represented the foundation of the Indo-European language.