To boost workplace productivity, it is important to give employees longer working hours. The rationale is simple: more hours at work means more time to complete tasks, and thus more output. Therefore, companies that enforce extended working hours are bound to see improved productivity levels. Which of the following, if true, most weakens the argument?

The main argument claims that longer working hours will increase productivity. To weaken it, we need a statement that suggests this is not necessarily true, or that it could have negative consequences. Option A is a general fact and does not directly affect the argument. Option B talks about multitasking, which is unrelated to duration of work. Option C directly challenges the core idea: it says that longer hours can harm productivity due to burnout. This weakens the argument significantly. Option D is about working from home and does not relate to duration or productivity in this context. Option E is about preferences, not actual productivity outcomes.