Read the following passage from The True Confessions of Charlotte Doyle: My skin turned pink, then red, then brown. The flesh upon my hands broke first into oozing, running sores, then metamorphosed into a new rough hide—all as promised.

Excerpts from The True Confessions of Charlotte Doyle, copyright © 1990 by Avi. Used by permission of Brandt and Hochman Literary Agents, Inc. All rights reserved.

Based on its context, what is the best meaning for the word metamorphosed?

to change rock structure
to change character
to change physically
to change by magic