A current carrying loop consists of 3 identical quarter circles of radius R, lying in the positive quadrants of $x-y ,y-z$ and $z-x$ planes , with their centers at the origin joined together . Find the direction and magnitude to $\overrightarrow{B}$ at the origin .

Question

$\begin{array}{1 1} \frac{\mu_0}{8R} (\hat i +\hat j+ \hat k) \\ \frac{\mu_0}{4R} (\hat i +\hat j+ \hat k) \\ \frac{\mu_0}{2R} (\hat i +\hat j+ \hat k) \\ \frac{\mu_0}{4 \pi R } (\hat i +\hat j+ \hat k) \end{array} $