Answer:
(a) ∠3
Explanation:
Where three lines are coincident at one point, and the angles created are numbered clockwise from 1 to 6, you want to know the angle adjacent to angle 4.
Adjacent angles
Adjacent angles share a vertex and one side. Neither is interior to the other.
In the given diagram, angles 3 and 5 are adjacent to angle 4. The one of these that is on your answer choice list is ...
Angle 3 is adjacent to Angle 4