Concept:Assessment is a tool to evaluate and document students' learning progress and needs.Explanation:The main purpose of assessment is to understand how far students have progressed. It shows what students already know and where they need support. Assessments track skill development over time. They also help teachers improve instruction. While assessments can assign grades or find score ranges, those are not the primary goals. The core aim is to support learning by identifying growth areas.Answer:Option B: understand students' learning progress.