The number of mistakes after $t$ updates to the weight vector is:
$$
\gamma^2 t^t \leq\left\|w^t\right\|^2 \leq t R^2
$$
For $t=11$, we have:
$$
121 \leq\left\|w^{11}\right\|^2 \leq 11 \times 16
$$
From this, we get:
$$
121 \leq\left\|w^{11}\right\|^2 \leq 176
$$
From the options given, we see that $\left\|w^{11}\right\|^2=150$ is valid.