Final answer:
The comma is used in the sentence because it is placed before the subject 'you' after an infinitive phrase.
Step-by-step explanation:
The comma is used in the sentence you provided because it is placed before the subject 'you' after an infinitive phrase. This follows the Exception (Rule 3) which states that a comma is used to separate the subject from the rest of the sentence when it is introduced by an introductory phrase. In this case, the comma helps to clarify the structure and meaning of the sentence.