Which of the following can be an early sign of Alzheimer's disease?

Memory deficits are indeed one of the hallmark early signs of Alzheimer's disease. Individuals in the initial stages of this condition often experience challenges with memory, particularly in recalling recent events or learning new information. This impairment reflects the brain's deterioration in areas responsible for memory, cognitive processing, and information retention.

As Alzheimer's progresses, various symptoms can manifest, but memory loss commonly marks the onset of the disease. Recognizing early signs allows for timely intervention and planning for care, which can be crucial for patients and their families.

The other symptoms listed, while they can occur in various conditions, are not as definitive for the early stages of Alzheimer's disease. Inability to perform complex tasks, visual hallucinations, or difficulty recognizing faces may associate with different neurological or psychological conditions rather than being primary indicators of Alzheimer's in its initial phases.