Final answer:
The typical final cure time for an elastomeric impression material is within 15 minutes after mixing, although the exact timing can vary based on the product used.
Step-by-step explanation:
The final cure time for an elastomeric impression material typically varies based on the specific type used, as well as the manufacturer's instructions. However, it's common for these materials to set within a short period after mixing, often ranging from 1 to 15 minutes. Based on options provided, curing times after 30 minutes (option A) or 1 hour (option C) would be unusually long, and thus less likely. Option D's within 5 minutes is too short for the final cure, although initial setting may occur in that time frame. Therefore, the most likely answer for when an elastomeric impression material can undergo final cure is B) within 15 minutes.