Which of the following is the correct conversion of this compound sentence to sentence to simple sentence using a prepositional phrase---- "He was terribly unhappy but he did not blame the girl."

In spite of being terribly unhappy, he did not blamed the girl

In spite in being terrible unhappy, he did not blame the girl

In spite on being terrible unhappy, he did not blame the girl

In spite of being terrible unhappy, he did not blame the girl