100 ml solution having 0.2 M HA $\left(\mathrm{Weak} \mathrm{acid}, \mathrm{Ka} =1.0\times {10}^{-5}\right)$ and 0.2 N NaA, 200 ml of 0.1 M NaOH has been added. Furthermore, diluted to 1L. Which of the following statement is correct?

Initially, the solution has pH equal to 5, that is before addition of NaOH

After the addition of base, the solution losses buffering action and can be restored after the addition of acid.

After the addition of NaOH, the pH of solution increase by four units

In the final solution, the concentration of $\left[{\mathrm{OH}}^{-}\right] is {10}^{-9}M$