Answer: The correct option is
(C) x = 30.
Step-by-step explanation: We are given to find the value of x from the figure shown.
From the figure, we note that the angles with measures (x+90)° and 4x° are vertically opposite angles.
Since the measures of two vertically opposite angles are equal, so we must have

Thus, the required value of x is 30.
Option (C) is CORRECT.