The correct answer is C. of.
The preposition “of” is used to indicate possession or ownership. In this case, the man succeeded in getting possession of his land after a long court case. This means that he was able to regain ownership of the land that he had previously lost.
The other options are not correct because they do not indicate possession or ownership. The preposition “for” is used to indicate a purpose or goal. The preposition “to” is used to indicate a destination or direction. The preposition “with” is used to indicate a means or instrument. The preposition “against” is used to indicate opposition or resistance.
In this case, the man was not trying to achieve a purpose, reach a destination, use a means, or oppose something. He was simply trying to regain ownership of his land. Therefore, the preposition “of” is the correct choice.