The correct answer is C. IBM Robotic Process Automation distinguishes bots by their operating mode. Attended bots work alongside human users and are typically launched on demand to help complete repetitive or structured tasks during a user session. They support productivity by assisting the user in real time, often through IBM RPA Launcher or user-triggered execution. Unattended bots do not require human help at execution time. They are scheduled, orchestrated, or called through APIs and commonly run on servers or virtual machines using configured credentials and runtime capacity. Option A is incorrect because attended status is not defined by cognitive capability. Option B reverses the definitions. Option D incorrectly implies that attended bots handle independent large-scale workloads while unattended bots are restricted to narrow applications. In solution architecture, attended automation is best suited for front-office assistance and human-in-the-loop productivity, while unattended automation is best suited for back-office, scheduled, integrated, and autonomous process execution. Reference/topics: IBM RPA, attended automation, unattended automation, RPA Launcher, Bot Runtime, scheduled and orchestrated scripts.