Bailey attends her 20th high school reunion and realizes that she would have great difficulty with names if people were not wearing nametags. Her inability to remember the names of people she spent so much time with 20 years earlier is MOST likely caused by:

Her inability to remember the names of people she spent so much time with 20 years earlier is MOST likely caused by damage to various parts of the parietal lobe or the temporal lobe of the brain.

Explanation:

Anomic aphasia: is a type of aphasia known by problems of recalling words, names, and numbers.

Transience

Explanation:

This refers to the state in which an individual's  specific  memory deteriorate  with time.That is gradual fading of an individual  particular memory of an event  with time. it is occurs when  the information an individual  is  trying  to retrieve from the memory  is impeded by another similar information. This is based on  interference theory.And it can be proactive interference in which old memory impeded ability to form  new memories or retroactive in which  old memories are modified by the new ones, which  replaced them.

Generally encoding failure forms the basis of  transience. if the information is not properly stored for processing and future retrieval, or if there was lack of contact (commonalities) with the point of information  it is may be difficult for the information to be retrieved.  This is because the  each time we  repeatedly recollect an information the hippocampus ( part of the brain for memory storage) altered the particular information so that  it will always be fresh memory, and easy to recollect.

Bailey loss of contact with the point of information(her colleagues ), and lack of seeing  her colleagues frequently  affected hippocamous alteration, leading to interference and therefore the TRANSIENCE in her memory retrieval

tell their parents and make sure she gets from a counselor or therapist. be supportive and be there for her. be a kind and good friend. spend time with her to make her feel like she's not alone. i'm not a professional but i really hope they stays strong.