What does aphasia typically affect?

Aphasia is a communication disorder that primarily affects an individual's ability to understand and produce language. This means that individuals with aphasia may have difficulty comprehending spoken or written words, as well as issues expressing their own thoughts and ideas through speech or writing.

The condition usually arises from brain damage, most commonly due to a stroke or head injury, impacting areas of the brain responsible for language processing. Thus, option B is correct as it accurately reflects the core deficits associated with aphasia, emphasizing the impairment in both understanding speech and effectively communicating thoughts.

While the other options touch on important functions, they do not align with the specific nature of aphasia. Aphasia does not generally influence physical coordination, memory retention, balance, or movement; these aspects may fall under the influence of other disorders or brain injuries but are not characteristic of aphasia itself.