The passage discusses how terminologies used in emerging industries are expected to become phatic expressions. To complete the passage, we need to provide a reason or explanation for this expectation.
Option (c) states that such terms used in emerging industries are not only excessively used but also new, leading to uncertainty about their exact definitions. This provides a plausible reason for the expectation that these terms will eventually become phatic expressions. As they are used frequently but lack precise definitions, they may lose their inherent meaning over time.
Option (a) suggests that the inherent meaning of a term is primarily determined by its frequency of use. While this may be true in some cases, it doesn't directly address the context of emerging industries and their terminologies.
Option (b) states that the terms in emerging industries are newly-coined and expected to be in use for a considerable period of time. This contradicts the idea that these terms will eventually become phatic expressions.
Option (d) claims that terminology used in one field is usually not applicable in other unrelated fields. This is not relevant to the discussion of terminologies becoming phatic expressions in emerging industries.
Option (e) suggests that emerging industry types can be analyzed in terms of existing terms from linguistics. While this may be true, it doesn't provide an explanation for why the terminologies in these industries are expected to become phatic expressions.
Therefore, the option that best completes the passage is (c) not only are such terms used excessively, but many of them are so new that users are unsure of their exact definitions.