Angle 6 and angle 4 are consecutive interior angles.
As Oak and Elm are parallel, angles 6 and 4 are supplementary and the sum of their measures is 180 degrees.
Then, we can write:
Answer: Option D, m<4 = 110 degrees.
Note: if you compare angles, 4 is the corresponding angle to 8 (they have the same measure). In the picture, 6 and 8 are easily seen as supplementary, adding 180 degrees between the two measures.