16. If the sum of first 11 terms of an A.P., \( a_{1}, a_{2}, a_{3}, \ldots \) is \( 0\left(a_{1} \neq 0\right) \), then the sum of the A.P., \( a_{1}, a_{3}, a_{5}, \ldots, a_{23} \) is \( k a_{1} \), where \( k= \)
1) \( -\frac{121}{10} \)
2) \( \frac{121}{10} \)
3) \( \frac{72}{5} \)
4) \( -\frac{72}{5} \)
