$A$ very long conducting wire is bent in a semicircular shape from $A$ to $B$ as shown in the figure. The magnetic field at point $P$ for the steady current configuration is given by:

• A
  $\frac{\mu_0 i }{4 R }\left[1-\frac{2}{\pi}\right]$ pointed into the page
• B
  $\frac{\mu_0 i }{4 R }$ pointed into the page
• C
  $\frac{\mu_0 i }{4 R }$ pointed away from the page
• D
  $\frac{\mu_0 i }{4 R }\left[1-\frac{2}{\pi}\right]$ pointed away from the page