Use each of the following figures only once to form three group. The three groups Thus, formed are:

• A. (1, 3), (2, 5, 4), (6, 7)
• B. (1, 7), (2, 5, 4), (6, 3)
• C. (1, 3), (2, 6, 4), (5, 7)
• D. (7, 3), (2, 5, 4), (6, 1)