## Discussion Forum

Que. | Given relations r(w, x) and s(y, z), the result of
SELECT DISTINCT w, x FROM r, s is guaranteed to be same as r, provided |

a. | r has no duplicates and s is non-empty |

b. | r and s have no duplicates |

c. | s has no duplicates and r is non-empty |

d. | r and s have the same number of tuples |

Answer:r has no duplicates and s is non-empty |