Final answer:
2) The needle was contaminated with a harmful substance
The reason for immediate treatment at the hospital and follow-up treatment by her primary care provider is that the needle was contaminated with a harmful substance.
Step-by-step explanation:
The reason for immediate treatment at the hospital and follow-up treatment by her primary care provider is option 2) The needle was contaminated with a harmful substance. When Cindy stuck her finger with the needle, there is a risk of exposure to harmful substances like infectious agents or chemicals that may cause serious health problems. Immediate treatment at the hospital is necessary to assess the extent of the injury, administer any necessary antidotes or treatments, and to prevent further complications.