Respuesta :

There's a simple formula for finding the arc length.
   
In radians:
A = θ*r = (2pi/3) x 4 cm = 8*pi/3 cm

Therefore, the answer is letter A  8*pi/3 cm.

I hope my answer has come to your help. God bless and have a nice day ahead!

The arc length would be 8pi/3