What is the magnetic field at the centre of arc in the figure below?

Options

1. A$\dfrac{{\mu}_{0}}{4\pi} \cdot \dfrac{2I}{r}\left[\sqrt{2} + \pi\right]$
2. B$\dfrac{{\mu}_{0}}{4\pi} \cdot \dfrac{2I}{r}\left[\sqrt{2} + \dfrac{\pi}{4}\right]$
3. C$\dfrac{{\mu}_{0}}{4\pi} \cdot \dfrac{I}{r}\left[\sqrt{2} + \pi\right]$
4. D$\dfrac{{\mu}_{0}}{4\pi} \cdot \dfrac{I}{r}\left[\sqrt{2} + \dfrac{\pi}{4}\right]$