The height , in feet, of a certain tree can be modeled by the equation , where is the number of years since it was planted. Which of the following describes the meaning of the in this equation?
The initial height, in feet, of the tree when it was planted
The increase in the height, in feet, of the tree each year
The number of years it takes for the tree to grow 5 feet
The maximum height, in feet, the tree can reach
