https://academic.oup.com/ptj/article/96/7/1057/2864925
this article is probably you’re best reference to grasp how to navigate the low treatment classification. You’re absolutely correct that manipulation would be appropriate, but only if you we certain centralization had plateaued with directional exercises, we didn’t state that specifically but set the table knowing that people would easily make that assumption.
On the actual OCS exam, never assume, go strictly with the facts given. They can only test you on what is explicitly asked. And rest assured that if a question is written poorly, it will be consistent answered incorrectly and they will throw the question out.
I hope thats helpful?