Answer
A)75
B)65
C)60
D)70

Answer:
Let's denote O as center of circle.
=> Two isosceles triangles AOB and EOF are congruent (SSS).
Because AO = BO = EO = FO = radius of circle O, AB = EF = 8
=> Arc AB = AOB = EOF = Arc EF = 65 deg.
Hope this helps!
:)