OG详解-OG8 文法 Q5

Choice D is the best answer. The convention being tested is subject-verb agreement. The plural verb “attest” agrees in number with the plural subject “trailblazing accomplishments.” 
Choice A is incorrect because the singular verb “attests” doesn’t agree in number with the plural subject “trailblazing accomplishments.” Choice B is incorrect because the singular verb “has attested” doesn’t agree in number with the plural subject “trailblazing accomplishments.” Choice C is incorrect because the singular verb “is attesting” doesn’t agree in number with the plural subject “trailblazing accomplishments.”