The answer is d the last one
First find angle EBC.
The are for a triangle is 180 degrees.
It is a right triangle and has a right angle.
180 - (90 + 50)
180 - 140
angle EBC IS 40
NOW FIND X
The line is 180 degrees.
180 -40 = 140
X = 140 DEGREES
It will be 49% out of 100