Which of the following is present in atmosphere?

The correct answer is: All of these

The correct option is d)All of these.

• Airborne dust particles, often referred to as particulate matter (PM), come from a variety of sources. Both size and chemical composition vary greatly in relation to source nature and particle history.
• Pollen grains are small objects in the form of fine to coarse dust from the catkins of certain plant species. They contain pores through which the protein is distributed to the human upper respiratory tract. That means we breathe pollen almost everywhere.
• The amount of water vapor in the air is called absolute humidity. The amount of water vapor in air compared to the amount of water it can hold is called relative humidity.