What is the meaning of a single solid yellow line beside a traffic lane?

Answer: A — Passing is not allowed

A single solid yellow line beside a traffic lane indicates that passing is not allowed. This line is typically found on the left side of the lane, with a broken yellow line on the right side. This means that drivers should not attempt to pass other vehicles and must stay in their own lane. Option B is incorrect because parking is generally not allowed beside a traffic lane. Option C is incorrect because passing should not be done on the right side of the lane. Option D is incorrect because caution should always be exercised while driving, regardless of the lane markings.