Which statement about the earth’s atmosphere is true? Please help

A. A recent increase in carbon dioxide levels can contribute to a long-term cooling of Earth’s climate.

B. A recent decrease in carbon dioxide levels will increase plant growth on Earth.

C. In the past few decades, carbon dioxide levels have been rising.

D. In the past few decades, carbon dioxide levels have been falling.

:)

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.