Answer :
Final answer:
The heated airstream from a heat pump commonly operates in the range of 90-100 degrees Fahrenheit, which is sufficient for indoor heating needs without reaching the higher output temperatures of traditional furnaces.
Explanation:
The temperature of the heated airstream from a heat pump operating in the heating mode under typical conditions is approximately 90-100 degrees Fahrenheit (option a). Heat pumps are designed to transfer thermal energy from a colder area to a warmer one, and the temperature of the output air is often influenced by the efficiency of the heat pump and the external and internal temperature conditions.
Given the information provided, although we do not have exact figures for the heated airstream, under typical operation and moderate climate conditions, the output temperature is in the lower end of the domestic heating range, which often falls between 90-100 degrees Fahrenheit. This range is sufficient to raise the internal temperature of a space to comfortable levels without being as high as the temperatures produced by traditional furnaces.