The correct option is A Of
Preposition 'of' is used to indicate reference or amount generally. So, Option D is the correct answer as ‘of’ serves as a reference to the person. Preposition 'in' can be used to show a state or condition, 'on' means 'on the top of' or 'on the surface of,' and 'by' is used to show who or what does, creates or causes something. So, Options A, B and C cannot be used as they would not serve as a pointer and render the sentence meaningless.