The correct answer is A. Growing degree-days.
Growing degree-days (GDD) are a measure of the accumulated heat that a plant needs to grow and develop. They are calculated by taking the average temperature of a day and subtracting a base temperature, which is typically 50 degrees Fahrenheit. The number of GDDs that a plant needs to grow varies depending on the type of plant. For example, corn needs about 1,200 GDDs to reach maturity, while soybeans need about 1,000 GDDs.
GDDs are used as a guide to planting and for determining the approximate date for harvesting crops. Farmers can use GDDs to determine when to plant their crops so that they will mature at the optimal time. They can also use GDDs to determine when to harvest their crops so that they will have the best quality and yield.
B. Heating degree-days are a measure of the amount of heat that is needed to raise the temperature of a building or other structure above a certain base temperature. They are calculated by taking the average temperature of a day and subtracting the base temperature. The number of heating degree-days that a building or structure needs to be heated varies depending on the climate and the type of building or structure.
C. Cooling degree-days are a measure of the amount of heat that is needed to lower the temperature of a building or other structure below a certain base temperature. They are calculated by taking the average temperature of a day and subtracting the base temperature. The number of cooling degree-days that a building or structure needs to be cooled varies depending on the climate and the type of building or structure.
D. Mean annual temperature is the average temperature of a location over a period of one year. It is calculated by taking the average of the monthly temperatures. The mean annual temperature can be used to determine the climate of a location and to predict the weather.