Which maintains the tone established in these three sentences?

few people or animals were awake at this hour. it was peter's favorite time of day. he moved quietly down a path, noticing the sun peeking through the branches overhead and the soft, moist ground underfoot.

a)peter shook his head in disgust when he discovered piles of trash on the trail.
b) peter tried to remain calm when he heard a frightening shriek behind some bushes.
c) peter yawned with boredom and wondered how anyone could like being outside so much.
d) he and his thoughts continued to wander as he smiled and breathed in the fragrant morning air.