What motivated Martin Luther to write and nail his 95 theses to the church door in Wittenberg?

A. he was unhappy with the outcome of the Crusades and that the great city of
Constantinople had fallen to the Ottoman Turks

B. he believed the Roman Catholic church should have worked harder to sell indulgences
because he believed people needed them

C. he was frustrated that the Christian church had split into two parts during the Great
Schism in 1054

D. he was angry with the Roman Catholic church for selling indulgences