To determine the percentage of the citizen population that had slave ancestry by the late Republic, we need to look at the known historical data.
The correct percentage is 50 percent.
This means that out of the entire citizen population, half of the individuals had slave ancestry. This figure underscores the significant impact and integration of former slaves and their descendants within the broader society of that time.
So, the correct answer to the question is:
○ 50 percent.
