What does 'usability' refer to in the context of technical documents?

In the context of technical documents, 'usability' refers specifically to the ease with which users can navigate and understand a document. Usability encompasses various factors that contribute to a user's experience with a document, including clarity, coherence, organization, and the ability to find and effectively use information. A document that is usable is designed with the audience in mind, ensuring that users can easily access the information they need and comprehend it without difficulty.

Navigation features, such as headers, lists, and indexes, are essential components that enhance usability, allowing readers to skim and locate information quickly. Additionally, clear language and logical organization help ensure that content is not only accessible but also understandable. Thus, the focus on user experience is paramount in defining usability in technical writing, making option B the correct choice.