Which choice best states the main purpose of the text?
A
To discuss von Ahn’s invention of reCAPTCHA
B
To explain how digital scanners work
C
To call attention to von Ahn’s book-digitizing project
D
To indicate how popular reCAPTCHA is
Explanation
Correct answer: A.
Choice A is the best answer because it most accurately states the main purpose of the text. After providing a brief introduction to computer scientist Luis von Ahn, the text focuses on discussing how von Ahn’s digitization work led to the invention of a digital security test known as reCAPTCHA.
Why the other choices are wrong
Choice B
Choice B is incorrect because the text doesn’t address how digital scanners work.
Choice C
Choice C is incorrect. Although the text mentions von Ahn’s book-digitizing project, that information is provided as a detail, not as the main purpose of the text.
Choice D
Choice D is incorrect because the text doesn’t provide any indication of reCAPTCHA’s popularity; instead, it describes reCAPTCHA’s origin.