Tai grows plants in a container called a terrarium, as shown below. He keeps the terrarium on a sunny windowsill. The terrarium is closed, so Tai cannot add water to the plants. However, the plants have enough water to grow. Which of these statements best explains why the plants always have enough water?

a The air cannot hold all of the water vapor.
b Water is unable to evaporate from the soil.
c The plants take up water and store it in their stems and leaves.
d Energy from the sun cycles water through the soil, the plants, and the air.