On wet, slippery and icy roads, you should...?

Answer: B — Turn brake retarders off

The other options are incorrect because increasing speed would only increase the risk of losing control on wet, slippery or icy roads. Hight beams would provide better visibility, but not necessarily improve traction on slippery surfaces. Regular application of brakes can be counterintuitive and lead to further loss of control on slippery roads. Turning brake retarders off, would reduce the risk of wheels locking up and improve steering by allowing you to better regulate the speed of the vehicle.