Which of the following words is an example of borrowing?

The word "futon" is an example of borrowing because it originates from Japanese and has been adopted into English to describe a specific type of bedding that can be used as a bed or a sofa. Borrowing refers to the process by which one language takes words from another language, often adapting them for use in its own lexicon.

In this case, "futon" carries with it the cultural significance of its Japanese roots, representing a traditional bedding style. This phenomenon illustrates how languages evolve and expand through contact with other cultures, integrating foreign terms that fill specific semantic gaps in the borrowing language.

In contrast, "piano," while also borrowed from Italian, does not demonstrate borrowing in the specific context of a distinctive cultural practice. The other choices, "happy" and "strong," are native English words with Old English origins and do not reflect the concept of borrowing from another language.