The x-intercept of a graph represents the point where the graph crosses the x-axis. In the context of your question regarding the hot air balloon's descent, the x-intercept indicates the time when the balloon has reached the ground level (0 feet).
Choosing the correct option based on this understanding, the appropriate response is:
It will take the balloon 30 minutes to land after starting the descent.
This means that the balloon will be on the ground after descending for 30 minutes.