The correct ois D. -17.5 degrees Step-by-step explanation: The daytime temperature in Apple Valley is falling by 2.5 degrees each day Therefore, Change in the temperature each day =-2.5 degrees Now, we need to find the net change in the daily temperature after one calendar week Now, number of days in one calendar week = 7 So, Net change in the daily temperature after one calendar week = Daily change × Number of days in one calendar week Net change in the daily temperature after one calendar week =-2.5 x7 # Net change in the daily temperature after one calendar week =-17.5 degrees Therefore, The correct option is -17.5 degrees