Step 1: Understand mirror imaging
A mirror placed vertically on the right side will reverse the sequence of characters horizontally while maintaining their vertical orientation.
Step 2: Reverse the order
Original: A N S 4 3 Q 1 2
Mirror image order: 2 1 Q 3 4 S N A
Step 3: Apply shape reversal
Digits and letters will appear reversed left-to-right but retain the top-bottom orientation. The option that matches this transformation is option (b).
\[
\boxed{\text{Option (b)}}
\]