Which describes the letter that belongs where the question mark is? help plz

At a continent-continent convergence,

In a 2010 article “fact check: eastern u.s. earthquake risk” by chris mould, the author provides as evidence the following statement by the united states geological survey: “although earthquakes may be less frequent in the eastern u.s., … urban areas in the east could face bigger losses because the shaking would affect much larger areas than similar quakes in the west. in addition, most homes and buildings in the east are not designed to withstand earthquakes.”this statement directly relates to which of the following concepts? a. vulnerabilityb. hazardc. riskd. severity

What is the difference between the cultures of central asia and the caucasus region? the majority of people in central asia are muslim; the majority in the caucasus region are christian. the primary language in central asia is armenian; the primary language in the caucasus region is russian. central asia has been plagued by ethnic unrest; the caucasus region has had little ethnic conflict. the effects of soviet rule can still be seen in central asia; the caucasus region has developed its own identity since the fall of the ussr.