Your answer would be B. 58°. This is because the two triangles ABF and EDG are congruent as they have the same sides, which means that the angles are the same also, so angle ABF is 81° and angle DEG is 70°.
Because angles in a triangle add up to 180°, we can add 81 and 70 to get 151°, and then subtract that from 180 to get 29°, which is angle BFA and DGF.
As we are told that GC ≈ FC, we know that CGF is an isosceles triangle and we can therefore add together 29 and 29 to get 58°, and then subtract that from 180° to get 122° as angle GCF.
Finally, we subtract 122 from 180 because angles on a straight line add up to 180°, which means your final answer is 58°. I hope this helps! Let me know if you have any questions :^)