What is the minimum legal tyre tread depth?

Answer: A — 1.6mm across central 3/4 of tyre all the way around

The minimum legal tyre tread depth is 1.6mm across the central 3/4 of the tyre all the way around. This means that the entire central 3/4 of the tyre must have a tread depth of at least 1.6mm in order to be considered legal. Option B is incorrect because it states that the entire tyre must have a tread depth of 2.0mm, but this is not the minimum legal requirement. Option C is incorrect because it mentions "selective parts" of the tyre, which is not a clear and specific measurement. Option D is incorrect because it mentions a tread depth of 3.0mm, which is higher than the minimum legal requirement.