He parted . . . . . . . . all his property.

The correct preposition to use in this sentence is "of". The sentence should read, "He parted of all his property." The preposition "of" is used to indicate possession or association. In this context, it signifies that he separated or distributed his property among others.

Option A: on is not the correct answer as it does not convey the intended meaning of dividing property.

Option B: in is not the correct answer as it does not convey the same meaning as "parted." "In" is used to indicate location or a state of being.

Option D: over is not the correct answer as it does not accurately convey the idea of dividing property.

Given the options provided, the correct answer is Option C: of.