This simply means that a person relaxes his/her thoughts or stops overthinking.
"Snails pace" is used to strengthen the visual of how the person slows his thoughts. This is an exaggeration to help other people understand the pace of the person's thoughts.
The fragment that is made up of a complete predicate is option A. "could not be heard above the voices in the hallway"
In grammar, the predicate is defined as the part of the sentence that contains the verb and gives information about the subject.
Option A is the only option that contains a verb, in this case "could" and it is providing information about a subject we don´t know. The only options lack verbs,
Explanation:
Being young is overrated. Being old is underrated. Being in the middle is middle-rated. The only reason people don't pass smoothly—with acceptance, dignity, and age-appproriate rewards and responsibilities—from one stage to the next is because modern societies don't value humans. They value images and synthetic versions of how people should behave and act and buy—created by the diseased reality-distortion field of the media. All people are seen as throwaway, and once they reach a certain age, they have little value. Wisdom is for naught. And even youth is nothing unless bartered in some way in a marketplace of masks and images. All people are victims of this, at least until they see it and resist. Resist being made and seen as a cartoon of a human. You are fully human and just right for your age and perfect for who you are at every moment all the time throughout your life.