In what ways did the population of Europe use religion to deal with the devastation occurring because of the Black Death?

Since no one knew the cause of the plague, it was attributed to the supernatural (such as supposed Jewish sorcery) and, specifically, to God’s fury over human sin. Those who died of the plague were suspect of some personal failing of faith and yet it was clear that the same clergy who condemned them died of the same disease in the same way. Scandals within the Church, and the extravagant lifestyle of many of the clergy, combined with the mounting deaths from the plague to generate widespread distrust of the Church’s vision and authority.

under god i have placed my chiest strentgh and the safe guard to my loyal subjects

yup! you are correct it is b.