Which of the following conditions can be caused by the properties of diphenhydramine?

Diphenhydramine is an antihistamine that is commonly used to treat allergies, motion sickness, and insomnia. One of its significant side effects is its anticholinergic properties, which often lead to symptoms such as dry mouth and confusion, particularly in older adults.

Dry mouth occurs because diphenhydramine reduces saliva production, a common effect of medications that have anticholinergic properties. Confusion can arise from the central nervous system effects of the drug, especially in vulnerable populations. The sedative effects of diphenhydramine may also contribute to a state of confusion, particularly in individuals who are elderly or already have cognitive impairments.

While other options mention potential risks or effects that might be associated with medications, they do not align with the primary pharmacological effects and known side effects of diphenhydramine. Therefore, dry mouth and confusion align closely with the known impacts of diphenhydramine usage.