Answer:
The method that the sentence uses is Action.
Step-by-step explanation:
The author uses indirect characterization, which in this case is an action to describe Marcie's character. "Twisting her braid between her fingers, Marcie jumped whenever anyone entered the room" shows us that she is anxious or she gets happy when she sees people. The author does not directly tell us how the character is. He gives us indirect information that we have to interpret to build the representation of the character in our minds.