Which idea would best fit at the beginning of a personal narrative?

a. I decided to try a little harder to keep my side of the room neat and started putting my dirty clothes in a plastic bin under my bed.
b. My brother decided to stop complaining all the time, and he stopped bugging me whenever I left something out by mistake.
c. My brother and I get along much better now, and our parents are so glad we stopped arguing.
d. My brother and I share a bedroom, and we argue all the time because he’s neat and I’m messy.