When looking for modifiers you have to ask yourself, how is this being modified, in the sentence, rules become incredibly simple when added the phrase. that´s why the unlined phrase is modifyin rules.
Explanation: I choose Understand and got it wrong and i saw the right answer was Rules. I guarantee you its Rules if you want to get this correct. This was the only question that was wrong out of my entire test because i didn't pick Rules.
