Jane planted a marigold sapling in her garden and recorded its growth every week. The plants height, in inches, is modeled by the function h(x), where x is the number of weeks since Jane planted the sapling. What is true of the function as the x-values increase ?

a. the function is increasing but the avg rate of change is decreasing
b. the function is decreasing, but the avg rate of change is increasing
c. the function is increasing, and the avg rate of change is increasing
d. the function is decreasing, and the avg rate of change is decreasing