Solution

The correctly matched triplets are AEG, BFI and CDH. AEG: A mentions a comparison between the earnings of men and women; It also introduces the comparison between 'white people' which carried forward in E and concluded in G. E ends with the definite article 'the' which must be followed by a noun/noun phrase; the noun phrase 'highest pay grades' satisfies this grammatical condition in G. BFI: B introduces mammals' whiskers and lists example like 'rats' which is carried forward in F ('shrews'). I carries the idea forward by explaining the use of these whiskers. CDH: C mentions 'rock samples' and D carries the same idea forward (deep crustal rock). D also mentions microbes and H carries the idea forward by stating that these "have adapted to life within nutrient-poor, hairline fractures in the earth." Amongst these, only AEG and CDH are mentioned in the options.