Answer:
C. x=12
Explanation:
imagine a circle with is center being the corner with the 40 degree angle. and a radius of 19.
and now turn the picture by 90 degrees or 270 degrees (not important, this would be just to visualize things better).
x is actually sine of the 40 degree angle multiplied by the radius (19).
x = sin(40)×19 = 12 (12.21296...)