The correct option is D luminosity
There is nothing of inconsequence in the entire, which harbours almost entirely on the glowworms' ability to lead one to their destination. Their intelligence, tranquility and mortality are of no issue with the poet. He establishes the power of the luminescent insects from the very first line, comparing them with livid lamps. It is the luminosity of them that he addresses. Therefore, option C is the correct answer.