Final answer:
Philosophy does not presuppose that language is understood universally. Early philosophical movements and studies in linguistic anthropology point towards varying interpretations influenced by linguistic relativity and context, as demonstrated by Ludwig Wittgenstein's work and the Sapir-Whorf hypothesis.
Step-by-step explanation:
The question whether philosophy presupposes that language is understood in the same way by everyone is best answered by option b), No, understanding may vary. Early 20th-century movements like linguistic analysis implied that language problems might underlie many philosophical issues. Meanwhile, discoveries in linguistic anthropology and ideas such as the Sapir-Whorf hypothesis suggest that language influences thought and perception, making a homogenous understanding of language unlikely.
Ludwig Wittgenstein's work in philosophy shows a transition from believing in a fixed structure to recognizing the context dependency of language. His later work, such as 'Philosophical Investigations', highlights this shift and suggests that understanding can vary dramatically based on personal experiences and sociocultural factors.
In the realm of linguistic relativity, it is evident from various researches and hypotheses that language shapes our cognitive processes and that there are likely many linguistic universals rooted in our common human experiences and anatomy. This indicates that while there might be shared aspects of language understanding, individual interpretation and usage differ widely.