One major difference between work and school is:

The major difference between work and school primarily revolves around the structure and expectations of time commitment, which is why the correct answer is focused on the varied hours in work compared to school.

In school, students typically follow a structured schedule that includes fixed hours for classes, whereas work can have a more flexible or varied schedule depending on the nature of the job. Some jobs may require early mornings or late evenings, while others might offer different shifts or allow for flexible hours. This variability in work hours reflects the diverse demands of different professions and industries, making it distinct from the consistent timetable usually found in educational settings.

The other options do not capture a primary distinction between work and school. For example, not all work experiences are unpaid, as many jobs compensate employees; likewise, school does not inherently require more homework than work, as it depends on the type of job one has. Similarly, continuous testing is primarily a feature of school rather than a common practice in the workplace, where evaluations might occur less frequently or through different assessment methods.