Which sentence is most clearly written?

The first sentence is more clearly written because it follows a straightforward structure that prioritizes clarity and brevity. By placing "officers" at the beginning, it immediately establishes the subject and what they are doing—practicing scenario-based situations. This direct approach allows for easier comprehension, as readers can quickly grasp the main action and context without having to navigate through additional words or modifiers.

The second sentence, while still conveying the same meaning, uses a more complex phrasing with the structure "situations that are based on scenarios." This adds unnecessary complexity and can create confusion for the reader. The clarity of a sentence often benefits from a more straightforward arrangement of words, which the first sentence achieves effectively.