Tires of a vehicle with a GVWR of 4499 KG or less should have a tire tread of not less than:

Answer: A — 1.6 mm

The correct answer is 1.6 mm. This is because this tread level is the minimum requirement for most passenger vehicles, which typically have a GVWR of 4499 KG or less. Option B with 2.0 mm is incorrect because while it may seem like a better choice, it is above the minimum requirement and therefore unnecessary. Option C with 1.2 mm is also incorrect because it falls below the minimum requirement and could potentially be unsafe for the vehicle. Option D with 3.0mm is incorrect because it is well above the minimum requirement and again, unnecessary. Essentially, the recommended tread level of 1.6 mm strikes a balance between safety and practicality for vehicles with a GVWR of 4499 KG or less.