Answer:
A) by showing three different representations of the same object, thus questioning the nature of representation
Step-by-step explanation:
A. is the right answer. Joseph Kosuth did composition One and Three Chairs by placing a physical chair, hanging its photograph, and placing dictionary definition of the word chair. By this, he tried to point to the discussion about what is actually an object and how different representations can lead to different views of the same thing. He tries to ask us what is the most accurate representation and pointing to us that different representations have different meanings.
B. is not the right answer. Kosuth did not try to point out that the dictionary definition has the same meaning. On the contrary, he tried to say how they have different effects and meanings. Also, there was a photography of the object as well.
C. is not the correct answer. The point was not to show different forms of art as much as to show different meanings and ideas about the same object.