Which transitions show the correct relationships? Global Warming and Its Causes

Global warming is a result of an increase in greenhouse gases. Greenhouse gases are released into the atmosphere
deforestation and combustion of fossil fuels.
Deforestation is a major contributor to global warming. Forests help to maintain the levels of oxygen in the air that make it possible for us to survive.
, there has been a surge in the levels of carbon dioxide in the air
the depletion of vast stretches of forests.
, other factors, such as the release of CFCs from refrigerators and pollutants from industries into the atmosphere, are also responsible for global warming.

Which sentence in this excerpt from leo tolstoy’s the death of ivan ilyich suggests that ivan ilyich aspired to be part of the elite in society from a young age? a.ivan ilyich was  le phenix de la famille  as people said.  he was neither as cold and formal as his elder brother nor as wild as the younger, but was a happy mean between them—an intelligent polished, lively and agreeable man.b.  even when he was at the school of law he was just what he remained for the rest of his life:   a capable, cheerful, good-natured, and sociable man, though strict in the fulfillment of what he considered to be his duty:   and he considered his duty to be what was so considered by those in authority.c.neither as a boy nor as a man was he a toady, but from early youth was by nature attracted to people of high station as a fly is drawn to the light, assimilating their ways and views of life and establishing friendly relations with them.d.all the enthusiasms of childhood and youth passed without leaving much trace on him; he succumbed to sensuality, to vanity, and latterly among the highest classes to liberalism, but always within limits which his instinct unfailingly indicated to him as correct.e.at school he had done things which had formerly seemed to him very horrid and made him feel disgusted with himself when he did them;