A wheel of radius 1 meter rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is [BCECE 2005]

• A.                         \[2\pi \]
• B.                                  \[\sqrt{2}\pi \]
• C.             \[\sqrt{{{\pi }^{2}}+4}\]    
• D.             \[\pi \]