Running trees signify a fast-moving change in human life from childhood to old age. The correct answer, option 'C', captures the essence of this symbolism. Let's explore this answer in detail.

1. **Symbolism of Running Trees**: In literature and art, trees are often used as symbols to represent various aspects of life. The concept of running trees refers to the idea that trees, which typically grow slowly and steadily, symbolize the rapid pace at which human life progresses from childhood to old age.

2. **Life's Journey**: The running trees symbolize the journey of life, where the passage of time is represented by the quick movement of the trees. It signifies the continuous and inevitable march of life from birth to death, with each stage of life passing by rapidly, just like the running trees.

3. **Changing Seasons**: Another interpretation of running trees is the changing seasons of life. Just as trees change their appearance with the seasons (e.g., the vibrant colors of autumn leaves or the bare branches of winter), human life goes through different phases and experiences, each with its own unique characteristics and challenges. The running trees symbolize the swift transition from one season of life to another.

4. **Transience of Time**: The running trees also remind us of the transience of time. Life is fleeting, and time waits for no one. The image of the running trees serves as a reminder to cherish every moment and make the most of the time we have.

5. **Metaphorical Representation**: The running trees can be seen as a metaphor for the fast-paced nature of change in human life. Childhood, adolescence, adulthood, and old age pass by swiftly, leaving behind memories and experiences that shape our journey.

In conclusion, the running trees symbolize the fast-moving change in human life from childhood to old age. They represent the journey of life, the changing seasons, the transience of time, and the swift nature of life's transitions. This symbolism serves as a poignant reminder to appreciate and make the most of the fleeting moments that make up our lives.