D

Step 1: When a ray of light reflects off a mirror, the angle of incidence is equal to the angle of reflection.
Step 2: In this case, the angle of incidence on the first mirror is 50°. Therefore, the angle of reflection (r1) from the first mirror is also 50°.
Step 3: The angle between the two mirrors is given as 50°.
Step 4: The ray approaches the second mirror at an angle given by the difference between the angle of reflection from the first mirror and the inclination of the mirrors:
Angle of incidence on the second mirror (i2) = 180° - (angle between mirrors + r1) = 180° - (50° + 50°) = 80°.
Step 5: The angle of reflection (r2) from the second mirror will also be equal to the angle of incidence on it: r2 = i2 = 80°.
Step 6: Now, to find the net deviation, we consider the total deviation caused by the reflection from both mirrors.
The total deviation = (angle of incidence on the first mirror + angle of incidence on the second mirror) - (angle between the mirrors)
Total deviation = (50° + 80°) - 50° = 80°.
Therefore, the net deviation of the ray is 80°.
Hence, the correct answer is D.