Which of the following items in the child's room is a common source of health care-associated infection?

The correct answer is D: Bedside computer keyboard. This is because items such as computer keyboards in a child's room can harbor harmful bacteria and viruses that can be transmitted to the child, caregivers, or healthcare providers, leading to healthcare-associated infections. Keyboards are frequently touched and are often overlooked when it comes to cleaning and disinfection, making them a common source of infections. The other choices (A, B, and C) are less likely to be sources of healthcare-associated infections in a child's room as disposable diapers, protective gowns, and unopened formula bottles are typically designed to maintain hygiene and are not directly involved in transmitting infections like a contaminated keyboard.