Explanation:

- The eight consecutive odd numbers can be represented as: $n,n+2,n+4,n+6,n+8,n+10,n+12,n+14$.

- The average of these numbers is 16.

- So, $\frac{n+(n+2)+...+(n+14)}{8}=16$.

- This simplifies to $\frac{8n+56}{8}=16$.

- Solving for $n$, gives $n=9$.

- So, the numbers are 9, 11, 13, 15, 17, 19, 21, 23.

- The immediately preceding odd number to $9$ is $7$.

- Including $7$, the numbers are 7, 9, 11, 13, 15, 17, 19, 21, 23.

- The new average is $\frac{135}{9}=15$.

Option:1 - 15