Read the following passage and answer the question. Becket, now the Archbishop of Canterbury, refused to obey. The re-establishment of friendly relations failed and Becket punished priests who had cooperated with Henry. Upon hearing this news, Henry reportedly exclaimed, "Will no one rid me of this turbulent priest?" Four knights took Henry at his word and murdered Becket in Canterbury Cathedral, pictured above, in December 1170.

Which statement interprets the primary reason behind the events described in this passage?