Which action is primarily focused on the 'Understanding' category of Bloom's taxonomy?

The action of examining is primarily focused on the 'Understanding' category of Bloom's taxonomy. This category emphasizes comprehension and the ability to articulate the meaning of information. Examining involves analyzing the information, looking for relationships, interpreting data, and making sense of concepts. It signifies that a learner is not just recalling information but is able to break it down and explain it in their own terms.

In contrast, the other actions listed do not align as closely with the 'Understanding' category. Choosing suggests making a decision without necessarily engaging with the material deeply, repeating typically relates to memorization and recall rather than comprehension, and writing, while it can demonstrate understanding, is a more complex skill that includes application and synthesis of information. Therefore, examining stands out as the action most directly associated with achieving understanding in learning.