What is the path of totality during a solar eclipse? o a. the sun is behind the moon, which casts its shadow on earth. o b. the sun is between earth and the moon, which casts its shadow on earth. loc. the sun is between the moon and earth, which casts its shadow on the moon. d. the moon is behind the sun, which casts its shadow on earth.

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?