A). A group of railroad workers set off dynamite on a cliff that isn't in their path.
Explanation:
Joseph Conrad's popular work 'Heart Of Darkness' primarily deals with the issues of colonialism and its absurd and evil aspects. Conrad primarily aims to reveal the inner darkness of the colonizers and their exploitation of the resources(human and natural) of Africans in the name of civilizing them.
As per the question, option A i.e. 'A group of railroad workers set off dynamite on a cliff that isn't in their path' display the example of ineffectiveness of the colonialist activities in Africa as witnessed by Marlow. This reveals the primitive and grotesque character of the Africans. However, the chief aim is to highlight the inner void and darkness(the failure) of the colonizers who were looting Africa in the name of civilizing them. Thus, <u>option A</u> is the correct answer.
The correct answer among all the other choices is B) a pacifying tone to convince the audience that the United States will use nuclear technology for peaceful purposes and not for destruction. Thank you for posting your question. I hope this answer helped you. Let me know if you need more help.
