Answer is (D)
before $\wedge$ operation all three expressions are the same,
i.e.return true if for each tuple $t$ we have finite no of tuple $u$ in employee table for which they have same employee_name.
(I) but in $2^{\text{nd}}$ part, for each tuple $v$ in department there may exist infinite no of tuple $t$ for which they may not be equal.
i.e. true for finite no of tuples $\wedge$ true for infinite no of tuples, over all true for finite tuple.
(II) there may exist infinite no of tuple for which at least one tuple $v$ belongs to department table for which they may not be equal.
i.e. true for finite no of tuples $\wedge$ true for infinite no of tuples, over all true for finite tuple.
(III) this one actually true for finite no of tuples, as there may exist only finite tuple which may be equal to at least one tuple $v$ in
department. because department table contain finite no of tuple all tuple $t$ which are same may not be more than all tuple $v$ in
department table in case of equality operation.
i.e. true for finite $\wedge$ true for finite tuple, over all true for finite tuple.
So all TRC query will return finite tuple which implies all are safe.
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