A trip can be charged to this schema, stating any assumptions you make. 8. 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. R contains e but not f,g