Final answer:
A play most fully exists in its performance, where actors bring the story to life on stage.
Step-by-step explanation:
The play most fully exists in its performance. Unlike a novel or a screenplay, a play is meant to be witnessed as a live experience with actors bringing the story to life on a stage. The effects and impact of a play are best experienced through the physical performance, including the actors' portrayal, the staging, and the interpretation of the script. A play is not fully realized until it is performed and witnessed by an audience.