What apparatus did Henry Cavendish use in his experiment to determine the gravitational constant?

• A. 1 bar, 1 small sphere and 1 large sphere
• B. 1 bar, 2 small spheres and 2 large spheres
• C. 2 bar, 1 small sphere and 2 large spheres
• D. 2 bar, 2 small spheres and 1 large sphere