Marvin walked along the shadowy sidewalk quickly. Suddenly, he heard
 the crack of a twig behind him. He turns around to see someone was
 following him. A chill ran down his spine.
 Which of these revisions corrects the inappropriate shift in verb tense?
 A. He turned around to see
 B. someorbis following him
 C. he was hearing the crack
 D. A chill runs down his spine