a
For first resonance, $\frac{\lambda}{4}=\ell_{1}+\mathrm{e}=11 \mathrm{cm}$
$(\because \text { end correction } \mathrm{e}=1 \mathrm{cm} \text { given })$
For second resonance, $\frac{3 \lambda}{4}=\ell_{2}+\mathrm{e}$
$\Rightarrow \ell_{2}=3 \times 11-1=32 \mathrm{cm}$