What does a sign that indicates "go straight only" mean for drivers?

Answer: C — Only straight movement is permitted

A sign indicating "go straight only" means that drivers are only permitted to continue straight ahead and do not have the option to turn right or left at that intersection. This type of directive is crucial for maintaining the flow of traffic and ensuring safety by clearly indicating the expected movement for vehicles approaching the intersection. By instructing drivers to proceed straight, it eliminates confusion and potential accidents that might arise if drivers were allowed to turn in other directions. Such signs are often placed in locations where turning could be hazardous or where the road configuration mandates that only straight travel is safe and appropriate.