What occurs during the active stage of bacteria?

During the active stage of bacteria, their primary focus is on growth and reproduction. In this phase, bacteria metabolize nutrients, divide, and increase in number rapidly. This exponential growth can occur under favorable environmental conditions, such as adequate temperature, moisture, and nutrients. The active stage is crucial for the bacteria's life cycle, enabling them to establish a population that can later continue to thrive or adapt to changing conditions.

In contrast, other processes like dormancy or spore formation indicate a transition away from active growth. While bacteria can enter states of dormancy or form spores as survival strategies in response to unfavorable environmental conditions, this is not a characteristic of the active stage. When bacteria die off, it indicates an inability to survive due to adverse conditions or lack of nutrients, which again is not aligned with the active stage's defining features. Therefore, the primary hallmark of this stage is vigorous reproduction and growth, making the choice affirming this aspect the correct one.