A New York student driver encounters a 'YIELD' sign. What should the instructor ensure the student does?

1. Come to a complete stop at every yield sign, even with no traffic or pedestrians
2. Slow down, check for traffic, and be prepared to stop if necessary; proceed when safe
3. Accelerate into the intersection to merge quickly before traffic reaches the yield point
4. Ignore the yield sign whenever the driver believes no traffic is immediately visible