Answer:
Option C. 49.5°
Explanation:
In the given figure arc QS is the diameter of the circle.
Angle formed at semicircle is 90°.
Therefore angle formed at center T will be 180°(∠QPS = 180° which is 2×∠QRS)
Now it is given arc QS = (4x - 18)° and equal to 180°
4x - 18 = 180
4x = 180 + 18 = 198
4x = 198
x = 198/4 = 49.5°
So the answer is 49.5°