Answer:
A. Best friends Kym and Tessa both decide to audition for the lead in the school play.
Explanation:
An inciting incident is an event in the plot where the main action that will bring forth the conflict in the plot happens to the characters. It hooks the readers into wanting to know what will happen in the coming scenes.
Among the various examples given in the question, the best inciting incident is when the two friends decided to audition for the same role in the school play. Both know it will anger or even hurt the other person's feelings but still decided to apply for the same role, which will lead to the main conflict between the two. And this will also hold the readers on suspense over who will get the role and what will happen after.
Thus, the correct answer is option A.