In the context of the graph modeling the descent of a hot air balloon, the x-intercept represents the time at which the balloon reaches the ground level (0 feet). Assuming the x-axis represents time in minutes and the y-axis represents height in feet, the x-intercept indicates when the balloon's height becomes zero. Therefore, the correct interpretation is:
It will take the balloon 30 minutes to land after starting the descent.
This means that at the x-intercept (30 minutes), the balloon reaches a height of 0 feet (ground level).