What does this sign mean? What does this sign mean?

• Possible answers:

   
• A. The width of the road is 6 feet 6 inches (2 metres)
• B. No vehicles over 6 feet 6 inches (2 metres) wide
• C. No vehicles over 6 feet 6 inches (2 metres) high
• D. Trailer length must not exceed 6 feet 6 inches (2 metres)