The two types of questions that he should practice to score well in the Critical Reading section of the SAT are B. sentence completion and D. passage based reading.
This section is mainly focused on testing the students' vocabulary, which is the aim of Sentence Completion questions, and it is also intended to test their reasoning and reading comprehension skills by means of the Reading Comprehension passages followed by multiple-choice questions.
The Sentence Completion questions are all multiple choice with five possible choices and they are arranged in order of difficulty. On the other hand, Reading Comprehension passages are not arranged in order of difficulty but many questions aim to ask about the main idea or overall point that a specific passage is trying to make.
