Question

Which of the following would be a relevant supporting detail in a personal narrative about winning your first tennis competition?

A. where you bought your first tennis racket
B. the first time you ever played tennis
C. what you ate for breakfast the morning of the big match
D. how you felt when you missed the first couple of serves that day

Answer 1

D. how you felt when you missed the first couple of serves that day

This answer is most relevant to the outcome of the given match

Answer 2

I would say D. The fact that you missed the first few serves would be very important to the story of how you ended up winning.  

A and B would be included if you were writing a full, detailed history of your tennis career.
C could be included but only if it was something to build emotion or something like that 

But how you felt when you missed the first couple of serves that day would be the best addition to your narrative.