Respuesta :

The length of an arc (s) is given in terms of the circle radius (r) and the central angle (θ) by
.. s = rθ . . . . . . . . . . . θ in radians

Your arc length is
.. s = (5 m)*(2π/3)
.. = 10π/3
.. ≈ 10.47 m

The 3rd selection is appropriate.