Unlike the use of headset telephones, which allow drivers to keep their hands on the wheel, all drivers are prohibited from using portable phones while driving.
(A) Unlike the use of headset telephones, which allow drivers to keep their hands on the wheel
(B) Besides using headset telephones, which allow drivers to keep their hands on the wheel
(C) Unless headset telephones, which allow drivers to keep their hands on the wheel, are used
(D) Other than the use of headset telephones, which allows drivers to keep their hands on the wheel
(E) Aside from using headset telephones which allow drivers to keep their hands on the wheel

[spoiler]I think both B & C mean same. But OE says B wrongly compares telephones with drivers. OA:C[/spoiler]