You're driving a double-deck bus. What's the minimum depth of tread required over three-quarters of each tyre's width? You're driving a double-deck bus. What's the minimum depth of tread required over three-quarters of each tyre's width?

• Possible answers:

   
• A. 0.8 mm
• B. 1 mm
• C. 1.6 mm
• D. 2 mm