Answer:
Volcanoes that have records of eruption are classified as active.
Step-by-step explanation:
Currently there is no way accepted worldwide by all volcanologists to define an "active" volcano, since the life of a volcano can range from months to millions of years.
For this reason a volcano could be considered active only in comparison to human life expectancy. Thus, scientists consider active volcanoes those who have unusual seismic activity or have new gas emissions that must be considered, that is, they are about to explode.
Taking this definition into account, any volcano that has had an eruption in the course of human life is defined as active.