Read the following excerpt from the article "vision, voice and the power of creation: an author speaks out," by t. a. barron, and answer the question that follows:

yet deeper than character, or even place, is another concept: voice. more than any other doorway to the imagination, i find this one the trickiest to open—and the hardest to close. for a character's true voice is heard, its tones, cadences, and ideas are long remembered.

the ancients [people from ancient history] used anima, in fact, to describe breath as well as soul. that is wholly appropriate, for in the breath—the voice—of a character lies its essential spirit. if the writer can truly hear the voice of a character, so will the reader.

which phrase explicitly states the author's attitude about voice?
a. it is the trickiest door to open.
b. the ancients invented it.
c. only the writer hears it.
d. the reader will always hear it.