Here, ABE + EBC = 180 [ Linear -Pair equation ]
42 + EBC = 180
EBC = 180 - 42
EBC = 138
Now, In a triangle, sum of all the angles would be equal to 180
EBC + BCE + x = 180
138 + 42 + x = 180
x = 180 - 170
x = 10
In short, Your Answer would be Option B
Hope this helps!