A) Give an example to illustrate the following: The join of two 3NF relations may produce a 3NF relation. Justify your example by providing a simple but concrete example (including schema, and FDs in the F set, etc.). If it is impossible to provide such an example, please explain why.

B) Give an example to illustrate the following: The join of two 3NF relations may produce a non-3NF relation. Justify your example by providing a simple but concrete example (including schema, and FDs in the F set, etc.). If it is impossible to provide such an example, please explain why.