How long do scientists estimate that the sea has been at its current level?

B. 2,500 years

Explanation:

As the current sea level has risen about 130 meters which is higher than histrionic mean sea levels. Where the last glaciation took place about 20,000 years ago. And last time the sea levels where higher was during the eemian period.

A 2014 Reuters analysis found that, before 1971, water reached flood levels no more than five days every year (on average) in several U. S. east coast cities. Since 2001, however, that number has risen to 20 days or more (on average).