Explanation:

- He persevered despite of difficulties.

- This phrase is incorrect. "Despite of" is not standard English usage. It should be "despite."

- He persevered because of difficulties.

- This suggests the difficulties were a motivating factor rather than an obstacle, which is not the intended meaning here.

- He persevered although difficulties.

- "Although" is used to introduce a contrast, but it doesn't fit grammatically in this sentence on its own without another clause.

- He persevered in spite of difficulties.

- "In spite of" is correctly used to indicate that he continued despite the challenges.