B: The sun shining on Earth
The woods are dark, deep and foreboding. It makes the reader anxious and nervous. However, when the speaker comes out of the woods and into the sun, there is a sense of calm. The sun shining after being in a dark place often brings about warmth and hope. The other options don't make sense. A bird in flight can also reveal hope, but this wasn't the first sight that gave the speaker a sense of calm. A leopard feeding her young doesn't have anything to do with a feeling of calm.
