The saturation voltage of the ideal op-amp shown below is $\pm 10$ V. The output voltage $v_{o}$ of the following circuit in the steady-state is

1. Square wave of period $0.55$ ms.
2. Triangular wave of period $0.55$ ms. square
3. Square wave of period $0.25$ ms.
4. Triangular wave of period $0.25$ ms