The correct answer is C. of.
The preposition “of” is used to indicate possession, origin, or a part of something. In this case, the speaker is telling the listener to ignore the person. The listener should not pay attention to the person, or take any notice of them.
The other options are not correct because they do not make sense in the context of the sentence. The preposition “about” is used to indicate a topic or subject. The preposition “on” is used to indicate a location or position. The preposition “in” is used to indicate a place or container.
Here are some examples of how the preposition “of” can be used:
- The book is about a boy who goes on an adventure.
- The house is on the corner of Main Street and Elm Street.
- The water is in the glass.
I hope this helps!