Which of the following conditions affects writing abilities?

Agraphia refers specifically to the impaired ability to write, which can result from brain damage affecting the areas involved in writing processes. Individuals with agraphia may struggle to form letters, organize written thoughts, or spell words, all of which are essential components of written communication. This condition is often linked to other neurological conditions and may manifest alongside other language impairments.

Understanding that the focus of the question is on writing abilities clarifies why agraphia is the most suitable answer, as its primary feature is writing impairment. Other conditions like alexia affect reading abilities, acalculia pertains to difficulties with mathematical calculations, and aphasia involves a broader range of language impairments, including speaking and understanding language, not limited solely to writing.