Final answer:
The yellow and black "recommended speed" sign indicates the recommended speed limit in the area, which advises drivers on a safe traveling speed but is not a legally enforceable limit.
Step-by-step explanation:
Sometimes a warning sign is joined with a yellow and black "recommended speed" sign. This indicates the recommended speed limit in that area, which advises drivers on a safe traveling speed for a particular stretch of road, especially where there are curves, turns, or other driving conditions that warrant caution.
The recommended speed is not legally enforceable like a maximum speed limit, but it serves as guidance to help drivers maintain control of their vehicle and navigate the road safely. The answer to the student's question is option 1) The recommended speed limit in that area.