Which of the following is a character of a low pressure system

The answer is A 
The air circulated in a clockwise direction in the northern hemisphere

A characteristic of a low-pressure system is that it is typically associated with cloudy weather and precipitation.

As per UCAR Center  for Science Education: "A low pressure system has lower pressure at its center than the areas around it. Winds blow towards the low pressure, and the air rises in the atmosphere where they meet. As the air rises, the water vapor within it condenses forming clouds and often precipitation too. Because of Earth’s spin and the Coriolis Effect, winds of a low pressure system swirl counterclockwise north of the equator and clockwise south of the equator. This is called cyclonic flow. On weather maps a low pressure system is labeled with red L."

Carbon dioxide is the correct answer