The correct answer is C. in.
The preposition “in” is used to express interest in a subject or activity. For example, “I am interested in history” or “She is interested in drawing and painting.”
The preposition “of” is used to express possession or ownership. For example, “The book is of great interest to me” or “The painting is of the Mona Lisa.”
The preposition “at” is used to express location or position. For example, “The museum is at 5th Avenue and 53rd Street” or “The painting is at the top of the stairs.”
The preposition “with” is used to express association or involvement. For example, “I am with the company” or “She is with the painting.”