Helen Burns was the best friend of Jane Eyre in Lowood institution, she was several years older than Jane and represented for her all the goodness of the Christian principles; Helen’s death is taken like she was too good for this world and cannot survive here, for Jane it symbolizes the loss of innocence hence at Helen’s last moments they two discuss the idea of God and Jane’s previous fear about this theme and the afterlife are relieved. The answer is C.
