Answer:
Option B - Jamie loses her best friend.
Step-by-step explanation:
Following through the narrative, we see the effect of peer pressure in play. Apparently, before Lynette turned 13 years old, Jamie used to be her best friend. However, since turning 13, she has gradually become more withdrawn from & the reason was because she was now hanging out with the 'Fab Thirteens'; the 'Fab Thirteens' were a group of folks who had clocked 13 years old. They excluded anyone who was 12 and below from joining their group; this was the reason why Jamie (the narrator) could not join the 'Fab Thirteens' - She was not yet 13 years old. As a result, Jamie loses her best friend, Lynette made evident by the statement "Gradually, Lynette stopped inviting me over after school" from the excerpt.
Hence, the significant event described in this excerpt is that Jamie loses her best friend (Lynette)