Final answer:
The sign indicating the end of a divided highway is the 'Divided highway ends sign'. It warns drivers that the separated lanes of traffic will soon merge into an undivided road layout.
Step-by-step explanation:
The sign used to show the end of a divided highway is option 3) Divided highway ends sign. Road signs are critical for directing drivers and ensuring safety on the roads. A Divided Highway Ends sign indicates that the separation between opposing lanes of traffic, often provided by a median or physical barrier, is coming to an end, and shortly, the road will no longer be divided. Drivers should prepare for this change by being aware of oncoming traffic in a now undivided road situation. It is imperative for drivers to understand the meaning of road signs to navigate safely and effectively.