Schema R1 has (A,B) as primary key and {A} as foreign key to R2[A] Schema R2 has {A} as primary key Check all the correct statements below about the following tables R1 (A, B, C, D) 1 b 1 2 b 2 1 de 1 R2 (A, E) 1 u 3 2 u V insert into R1 values (4, 'b', 'e',1) violates a primary key constraint insert into R2 values (4, 'u') violates a foreign key constraint delete from R2 where A=2 violates a foreign key constraint (assuming NO cascading deletions) delete from R1 where A=2 violates a foreign key constraint (assuming NO cascading deletions) insert into R2 values (2, 'w') violates a primary key constraint insert into R1 values (4, 'd', 'e',1) violates a foreign key constraint