Question 4 [ 6 points] Consider the relation R(A, B, C, D, E, F, G) with the following functional dependencies: { AB F, BD C, C A, CF BE, CE F} 4.1 Is {A, B, C} a superkey for R? Explain your answer. 4.2 Give a set of attributes that form a minimal key for R. Explain why your set is a minimal key