Plants, algae, and phytoplankton are the main components of the _________ carbon cycle.

• A. fast
• B. geological
• C. sedimentary
• D. slow

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the context of the carbon cycle. The carbon cycle is a biogeochemical process that describes how carbon moves through the Earth's systems, including the atmosphere, biosphere, hydrosphere, and geosphere.
2. Step 2: Recognize the role of plants, algae, and phytoplankton in the carbon cycle. These organisms are primary producers that perform photosynthesis, capturing carbon dioxide (CO₂) from the atmosphere and converting it into organic compounds.
3. Step 3: Differentiate between the types of carbon cycles. The 'fast' carbon cycle involves processes that occur over short timescales (days to years), such as photosynthesis, respiration, and decomposition. The 'slow' carbon cycle involves geological processes like rock formation and volcanic activity, which occur over millions of years.
4. Step 4: Analyze the options provided. Since plants, algae, and phytoplankton are involved in photosynthesis and other rapid processes, they are part of the 'fast' carbon cycle. The 'geological' and 'sedimentary' cycles refer to slower processes, while the 'slow' cycle explicitly contrasts with the fast cycle.
5. Step 5: Conclude that the correct answer is 'fast,' as these organisms are integral to the rapid exchange of carbon between the atmosphere and biosphere.