isolated grammar questions can be scored consistently and can sample many rules in a short time. High reliability makes such tests attractive for large programs. Paragraph 2: Real communication requires speakers to interpret context, organize ideas, and adjust language to purpose and audience. A learner may select correct forms in isolation yet struggle to use them coherently in a conversation or report. Paragraph 3: Performance tasks should therefore supplement rule-based items. The grammar questions measure one component accurately, but they do not cover the full ability the program claims to assess. Which answer best captures the relationship of paragraph 2 to the passage's purpose regarding language-test validity?