Read the excerpt from “The Snow-Queen.” “Now I must fly to warmer countries,” said the Snow-queen. “I must go and powder my black kettles!” (This was what she called Mount Etna and Mount Vesuvius.) “It does the lemons and grapes good.” And off she flew, and Kay sat alone in the great hall trying to do his puzzle. He sat so still that you would have thought he was frozen. Then it happened that little Gerda stepped into the hall. The biting cold winds became quiet as if they had fallen asleep when she appeared in the great, empty, freezing hall. She caught sight of Kay; she recognised him, and ran and put her arms round his neck, crying, “Kay! dear little Kay! I have found you at last!” But he sat quite still and cold. Then Gerda wept hot tears which fell on his neck and thawed his heart and swept away the bit of the looking-glass. He looked at her and then he burst into tears. He cried so much that the glass splinter swam out of his eye; then he knew her, and cried out, “Gerda! dear little Gerda! Where have you been so long? and where have I been?”
How does the protagonist move the plot forward in this excerpt?

A- Kay moves the plot forward by working on his puzzle.
B- Gerda moves the plot forward by entering the frozen hall.
C- Gerda moves the plot forward by freeing Kay with her tears.
D- The Snow-queen moves the plot forward by leaving Kay alone.