Final answer:
The 'usability divide' is not recognized as a stage of the digital divide, which comprises factors such as economic divide, accessibility divide, and empowerment divide, contributing to a knowledge gap and technological stratification.
Step-by-step explanation:
The stage that is not a stage of digital divide among the given options is the 'usability divide'. The digital divide refers to the uneven access to technology among different groups of people based on factors like race, class, and geography. The 'usability divide' is not commonly recognized as part of the stages in discussing the digital divide. The knowledge gap can be directly attributed to the digital divide because differential ability to access the internet leads to a differential ability to use the knowledge found on the internet.
The digital divide creates a knowledge gap, resulting in unequal opportunities for individuals in poorly funded communities compared to those in well-funded communities, affecting their potential employability in a technology-based job market. Research has indicated that technological use and internet access vary significantly by race, class, and age in the United States. Furthermore, even as access improves, the empowerment to effectively utilize that technology is not equally distributed, illustrating the multifaceted nature of the digital divide.