The correct answer to the question "Which of the following statements best describes “carbon fertilization”?" is Option 1: Increased plant growth due to increased concentration of carbon dioxide in the atmosphere.

Carbon fertilization is a phenomenon that occurs when plants experience an increase in the concentration of carbon dioxide in the atmosphere. As carbon dioxide is a vital component for photosynthesis, an increase in its concentration can lead to an increase in plant growth and productivity. This effect is commonly observed in crops, forests, and other vegetation.

Studies have shown that carbon fertilization can result in increased crop yields, which is beneficial for food security. It can also enhance the productivity of forests, which are important for mitigating climate change by absorbing carbon dioxide from the atmosphere.

Furthermore, the effect of carbon fertilization is supported by experiments that have shown that plants grown under elevated carbon dioxide concentrations have higher rates of photosynthesis, increased water-use efficiency, and reduced stomatal conductance. These effects can lead to increased biomass production, more efficient use of water resources, and improved plant health.

In contrast, the other options are not accurate descriptions of carbon fertilization. Option 2 is referring to the greenhouse effect, which is the trapping of heat by greenhouse gases in the atmosphere, including carbon dioxide, resulting in an increase in Earth`s temperature. Option 3 refers to ocean acidification, which occurs when carbon dioxide dissolves in seawater and forms carbonic acid, leading to a decrease in pH levels, making it difficult for marine organisms to survive. Option 4 is a general statement about the adaptation of living beings to climate change and is not specifically related to the phenomenon of carbon fertilization.

In conclusion, carbon fertilization refers to the increased plant growth due to the increased concentration of carbon dioxide in the atmosphere, which has beneficial effects on food security and the mitigation of climate change.