The Point $P ( x , y )$ Is on the Unit Circle in Quadrant IV

Multiple Choice

The point $P ( x , y )$ is on the unit circle in quadrant IV. If $y = - 5 / 6$ Find x

A) $x = \sqrt { 11 } , 6$
B) $x = - \sqrt { 11 } / 6$
C) $x = 11 / 6$
D) $x = - 11 / 6$
E) none of these