Find the set $A \cup \varnothing$.
\[
\begin{array}{l}
U=\{1,2,3,4,5,6\} \\
A=\{3,4,5,6\}
\end{array}
\]
Select the correct choice below and, if necessary
Final Answer: The set A \(\cup\) \(\varnothing\) is \(\boxed{\{3, 4, 5, 6\}}\).
Step 1 :Given the universal set U = \{1, 2, 3, 4, 5, 6\} and set A = \{3, 4, 5, 6\}.
Step 2 :The question is asking for the union of set A and the empty set.
Step 3 :The union of any set with the empty set is the set itself.
Step 4 :Therefore, the answer should be set A.
Step 5 :Final Answer: The set A \(\cup\) \(\varnothing\) is \(\boxed{\{3, 4, 5, 6\}}\).