Consider two relations R1(A, B) with the tuples (1, 5), (3, 7) and R2(A, C) = (1, 7), (4, 9). Assume that R(A, B, C) is the full natural outer join of R1 and R2. Consider the following tuples of the form (A, B, C): a = (1, 5, null), b = (1, null, 7), c = (3, null, 9), d = (4, 7, null), e = (1, 5, 7), f = (3, 7, null), g = (4, null, 9). Which one of the following statements is correct?

R contains a, b, e, f, g but not c, d.

R contains all of a, b, c, d, e, f, g.

R contains e, f, g but not a, b.

Consider two relations R1(A, B) with the tuples (1, 5), (3, 7) and R2(

1.	Consider two relations R1(A, B) with the tuples (1, 5), (3, 7) and R2(A, C) = (1, 7), (4, 9). Assume that R(A, B, C) is the full natural outer join of R1 and R2. Consider the following tuples of the form (A, B, C): a = (1, 5, null), b = (1, null, 7), c = (3, null, 9), d = (4, 7, null), e = (1, 5, 7), f = (3, 7, null), g = (4, null, 9). Which one of the following statements is correct?
A.	R contains a, b, e, f, g but not c, d.
B.	R contains all of a, b, c, d, e, f, g.
C.	R contains e, f, g but not a, b.
D.	R contains e but not f, g.
Answer» D. R contains e but not f, g.

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