Which is a common symptom of Alzheimer's disease?

Memory impairment is a hallmark symptom of Alzheimer's disease, reflecting the cognitive decline associated with this condition. Alzheimer's disease primarily affects the brain's ability to process and store information, which typically presents as difficulty in recalling recent events, learning new information, and ultimately affecting long-term memory.

As the disease progresses, individuals may struggle with recognizing familiar faces or places, recalling names, or following conversations, illustrating the profound impact on memory function. Hence, memory impairment is not only a common symptom but often one of the earliest signs noticed by family members or caregivers.

The other options do not align with the typical symptoms seen in Alzheimer's disease. Paranoia can occur in some individuals but is more associated with other types of dementia. Motor skill enhancement contradicts the nature of Alzheimer's, as it generally leads to decreased motor function and coordination over time. Increased sociability is also inconsistent, as individuals with Alzheimer's may withdraw socially due to confusion or frustration, rather than becoming more sociable.