(d) A digital alarm clock that rings at a set time every morning.
A digital alarm clock follows a fixed, pre-programmed instruction (ring at a set time) — it does not learn, adapt, or make decisions. The other options (robotic vacuum, chatbot, facial recognition) all involve AI techniques such as navigation algorithms, natural language processing, or machine learning. AI refers to machines mimicking human intelligence through algorithms and data; a simple alarm clock merely executes a hardcoded rule with no intelligence involved.