1. The problem asks to convert 3\pi radians into grads. \ngrads and radians relate by the conversion factor: $$1 \text{ radian} = \frac{200}{\pi} \text{ grads}.$$\n\n2. To convert, multiply 3\pi radians by the conversion factor: $$3\pi \times \frac{200}{\pi} = 3 \times 200 = 600 \text{ grads}.$$\n\n3. Hence, 3\pi radians equal 600 grads, which is not listed among the options a, b, c, or d.\n\nFinal Answer: 600 grads (none of the provided choices).