The bar graph above shows the release of carbon dioxide from fossil fuel burning in North America. Specifically, in points out that the amount of carbon dioxide released from fossil fuel burning greatly exceeds the amount of carbon dioxide that is taken up by forces crops and other ecosystems. Which of the three of the following are technologies and activities help in reducing this in balance.

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?