The idea that life is an unending struggle (option C) is affirmed by the sentence "Life is one continuous, competitive examination". An unending struggle is synonymous to a continuous examination. The struggle refers to the constant efforts one makes to win in something, here, in life. Hence, option C is correct. The passage does not focus on a life that is full of pain and suffering (this gives the passage a negative undertone), it speaks about the necessity of pain (in order to feel the joy when that pain is gone). Hence, A is incorrect. The idea in B (struggle or no struggle) does not represent the passage. In fact, the passage concentrates on the importance of struggle; with struggle there is joy: "Life indeed would be dull if there were no difficulties." Option B contradicts this line, hence, it is incorrect. Similarly, option D completely contradicts the passage. Lines like "there are no gains without pains.", "No victory is a real triumph unless the foe is worthy of the steel." (meaning that if there are no struggles, victory has no value) prove that option D does not represent the idea of the passage. Hence, D is incorrect.