What type of test is given when a teacher reads a trade book and then assesses student understanding?

The choice indicating curriculum-based assessment is the most suitable answer because this type of assessment involves evaluating students' comprehension, skills, and knowledge as they relate to the specific curriculum being delivered. When a teacher reads a trade book and subsequently assesses students' understanding, they are essentially checking how well students can apply what they've learned from the text within the context of the curriculum.

Curriculum-based assessments are typically integrated within the teaching process and allow educators to monitor students' progress in real time, making it a practical approach to ensure that students are grasping the material as it is taught. This method provides immediate feedback that can guide further instruction and support for students.

In contrast, standardized tests are designed to measure students' performance against a national or state benchmark, often without direct alignment to specific curriculum content. Diagnostic assessments aim to identify students' strengths and weaknesses prior to instruction and focus more on individual learning needs rather than immediate comprehension of a text. Formative assessments, while they reflect ongoing learning and may involve informal checks for understanding, tend to be more spontaneous and may not be as closely tied to specific curriculum materials as curriculum-based assessments are.