Final answer:
A bubble of size 1-2 mm is considered normal in a new dental cartridge. Small bubbles are not unusual but larger ones may compromise the cartridge. Dental professionals check bubble size for quality assurance.
Step-by-step explanation:
The question involves the acceptable size of a bubble within a dental cartridge. A bubble of size 1-2 mm (option b) is generally considered normal in a new dental cartridge. Bubbles of small sizes are common due to the manufacturing process and are typically not a cause for concern unless they exceed certain dimensions. The standard allows for a small bubble because it is understood that some air will be incorporated during the filling process. However, a bubble significantly larger may compromise the cartridge or indicate a problem with the seal, potentially affecting the dosage of the medication or the sterility of the product. Hence, dental professionals often check for the size of the bubble as part of their quality assurance processes before administering the anesthetic to the patient.