Every husband sits next to his wife, so we can say every husband-wife is a one-block.
There are $3$ husband-wife pairs, and each pair can sit in $2$ ways (Husband-Wife or Wife-Husband). The total number of seating arrangements is $2^3 = 8$ for each pair.
Now, consider these $3$ pairs as one unit each and arrange them in a circle, which can be done in $(3-1)!$ ways.
So, the total seating arrangements $= (3-1)! * 2^3 = 2 * 8 = 16.$
Correct Answer: A