Answer: Option C.
Step-by-step explanation:
Let as consider the complete question is same as question shown in the below figure.
In the figure m║n.
If a transversal line intersect two parallel lines then same sided interior angles are supplementary angles and their sum is 180 degrees.
[tex]3x+x=180^{\circ}[/tex]
[tex]4x=180^{\circ}[/tex]
Divide both sides by 4.
[tex]x=\dfrac{180^{\circ}}{4}[/tex]
[tex]x=45^{\circ}[/tex]
The value of x is 45 degrees.
Therefore, the correct option is C.
