Final answer:
Comprehension tests are assessments used to determine reading levels for expository texts, as they measure understanding through various question types, including critical thinking.
Step-by-step explanation:
The assessments that are used to determine accurate reading levels for expository texts are C) Comprehension tests. These tests typically feature a range of questions that might include multiple-choice, true/false, short answer, and critical thinking types. They aim to measure a student's understanding of the material, and can include Review Questions that assess students' mastery of the learning objectives and Critical Thinking Questions that demand a higher level of conceptual understanding. Other relevant assessment types are Cloze passages, which can evaluate reading comprehension and vocabulary in context by requiring students to fill in missing words.