Which of the following is not a clear example of how semantics has changed over time?

The option highlighting the misunderstanding between "guerilla warfare" and "gorilla warfare" demonstrates a semantic confusion rather than a change in meaning over time. The son mistakenly believes the term means something different, showing a lack of understanding rather than an evolution of the language itself. This illustrates a moment of miscommunication without reflecting the dynamic nature of language or changes in word meanings.

In contrast, other examples presented showcase genuine shifts in semantics where the terms have evolved or adopted new meanings culturally. For instance, the term "gay" has been reclaimed within the LGBTQ+ community, reflecting a broader societal acceptance and understanding of sexuality. Similarly, the phrase "killed it," in the context of sports or activities, has transitioned from a literal interpretation to a metaphorical one indicating success. The brand name "Kleenex" becoming synonymous with tissues also exemplifies how trademarked names can shift into general use, which indicates a cultural and linguistic development. Thus, the other choices demonstrate clear changes and adaptations in language that have occurred over time, unlike the confusion found in the example regarding "guerilla."