Correct option is : (2) \(\theta _1l_2 = \theta _2l_1\)
\(\theta = \theta _0 \sin \left( \sqrt{\frac{g}{l}}t+\phi\right)\)
or \(\alpha = -\frac{9}{l}\theta\)
\(\alpha _{max} = \frac{g}{l}\theta _0\)
\((\alpha _{max})_1 = (\alpha _{max})_2\)
\(\frac{\theta _1}{l_1} = \frac{\theta _2}{l_1}\)