The truth table for two sets, \( A \) and \( B \), performing the operation \( \bar{A} \cup \bar{B} \), yields which of the following results?
a) When \( A \) is true, and \( B \) is true then \( \bar{A} \cup \bar{B} \) is true.
b) When \( A \) is false, and \( B \) is false then \( \bar{A} \cup \bar{B} \) is false.
c) When \( A \) is false, and \( B \) is true then \( \bar{A} \cup \bar{B} \) is false.
d) When \( A \) is false, and \( B \) is true then \( \bar{A} \cup \bar{B} \) is true.
Is the answer \( a, \quad b, \quad c, \quad \) or \( d \) ?