It was calculated that a shell when fired from a gun with a certain velocity and at an angle of elevation \[5\pi /36\] rad should strike a given target. In actual practice, it was found that a hill just prevented the trajectory. At what angle (rad) of elevation should the gun be fired to hit the target

• A. \[\frac{5\pi }{36}\]                    
• B.        \[\frac{11\pi }{36}\]
• C. \[\frac{7\pi }{36}\]                    
• D.        \[\frac{13\pi }{36}\]