Question

The wind-chill factor:
A. Relates body heat loss with wind to an equivalent temperature with no wind
B. Indicates the temperature at which water freezes on exposed skin
C. Takes into account humidity and air temperature in expressing the current air temperature
D. Tells farmers when to protect crops from a freeze

Answer 1

Hint: Windchill is basically the lowering of the temperature of the body due to the exposure to lower-temperature air.

Complete answer: Wind chill is the temperature that feels like the outside temperature due to wind speed; the greater the wind speed, the greater will be the wind chill, and hence the colder the environment will feel.
Although wind chill is often described broadly as the 'feels like' temperature present outside, in real sense it only refers to the temperature the environment feels like because of the wind speed.
Other factors that also contribute to what the temperature feels like outside include sunlight, humidity, as well as precipitation.
Our bodies like to maintain a particular temperature, which is nearly 98.6 degrees Fahrenheit.

But when the environment is cooler compared to our bodies, then the particularly exposed skin in the extremities, tends to lose heat.
There are two methods we lose heat to a cooler environment namely, convection and radiation. In either method, heat always transmits from where there is more heat to where there is less heat.
So, this explains why in a cold environment our bodies will always lose heat.
A complex formula to calculate wind chill factor was used by weather services around the globe:

Wind Chill ($^o$F) = 35.74 + 0.6215T - 35.75V$^{0.16}$+0.4275TV$^{0.16}$

where, T = Air Temperature ($^o$F), V = wind speed (mph)

So, the correct answer is A. Relates body heat loss with wind to an equivalent temperature with no wind.

Note: The formula of wind chill factor was first developed by researchers from Antarctica in the 1940's to accurately calculate the temperatures.