The correct answer is B) Webbing. Webbing is the preferred lashing material for securing light vehicles aboard Ro-Ro (roll-on/roll-off) vessels. Webbing is strong, durable, and flexible, making it well-suited for securing vehicles of various sizes and shapes. Additionally, webbing is easier to handle and apply than chain or other metal lashing materials, which can pose a risk of damage to the vehicle's surface. The other options are not recommended for this application. Chain lever or turnbuckle (A) would be overly heavy and complex for securing light vehicles. Chain (C) is also not the optimal choice, as it can be more difficult to apply and may cause damage to the vehicle. Option D, "None of the above," is incorrect, as webbing is the appropriate lashing material for this purpose.