Write the resulting set using the listing method. \[ \{1,8,9\} \cup\{1,2,9\} \] Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. $\{1,8,9\} \cup\{1,2,9\}=$ (Use a comma to separate answers as needed.) B. $\{1,8,9\} \cup\{1,2,9\}$ is the empty set.

Step 1 ：The question is asking for the union of two sets. The union of two sets is a set that contains all the elements from both sets. If an element is in either of the two sets, it will be in the union set.

Step 2 ：In this case, we need to combine the elements from both sets, and remove any duplicates, because in set theory, each element is unique.

Step 3 ：Set 1 is \(\{1,8,9\}\) and Set 2 is \(\{1,2,9\}\).

Step 4 ：The union of the two sets \(\{1,8,9\} \cup \{1,2,9\}\) is \(\boxed{\{1,2,8,9\}}\).