Which of the following statement is true about woolen clothes?

All of these

The correct answer is option 4. All of these.

All three statements are true about woolen clothes:

1. Wool is a poor conductor of heat:  Wool fibers have a unique structure that makes them a poor conductor of heat. This property helps in retaining body heat, keeping the wearer warm.

2. There is air trapped in between the wool fibers: Wool fibers naturally trap air within their structure. The trapped air acts as an insulator, preventing the rapid escape of heat from the body.

3. Air trapped between woolen fibers prevents the flow of heat from our body to the cold surroundings:  The trapped air creates a barrier that hinders the transfer of heat from the warmer body to the colder surroundings. This insulation effect is beneficial in cold weather, providing thermal comfort.

So, the correct answer is "All of these."