Answer:
D). 'On the contrary'
Step-by-step explanation:
As per the question, option D displays the phrase i.e. 'on the contrary' from the given passage that indicates an opposing or contrary thought as this phrase signals the beginning of the ideas in the passage that would contradict the previous ideas presented. This phrase introduces the alternative idea that challenges the prior idea which states that 'every act of kindness is in fact purely selfish' by offering the contradictory claim that 'selfishly motivated giving has done a lot of good in the world'. Thus, the phrase 'on the contrary' signifies contrast and hence, option D is the correct answer.