A). Marlow says the colonialists had a hole dug out of "the philanthropic desire of giving criminals something to do."
Explanation:
"Heart of Darkness" by Joseph Conrad is an attempt to reveal and interrogate the roots of colonialism and condemn the inner void and greed of the imperialistic pursuits of colonizers.
As per the question, the quote in which Conrad employs sarcasm while retelling Marlow's tale is displayed through option A i.e. 'Marlow displays that these 'colonialists had a whole dug out of the philanthropic desire of giving criminals something to do'. <em>Conrad uses sarcasm in order to given an insight to the darkness of the colonizers and reveal the alternative side of their(colonizers') so called 'philanthropic lies' in a light-hearted manner which is the chief goal of sarcasm(to expose the human follies through humor and irony).</em> Thus, <u>option A</u> is the correct answer.
