$=A \sin \left(\omega t+\frac{\pi}{3}\right)$
Since, $x _1+ x _2+ x _3=0$
$x_3=A \sin \left(\omega t+\frac{4 \pi}{3}\right)$
So, $B=A$ and $\phi=\frac{4 \pi}{3}$
$(A)$ Restoring torque in case $A =$ Restoring torque in case $B$
$(B)$ Restoring torque in case $A < $ Restoring torque in case $B$
$(C)$ Angular frequency for case $A > $ Angular frequency for case $B$.
$(D)$ Angular frequency for case $A < $ Angular frequency for case $B$.

