Which is NOT involved in classical biological control?

Classical biological control involves the intentional introduction of natural enemies or beneficial organisms to manage pest populations. The primary goal is to establish a viable population of these beneficial organisms that can suppress pest populations effectively over time.

Releasing beneficial insects is a key component of this method, as it directly introduces organisms that can prey on or parasitize the target pests, thus helping to control their numbers.

On the other hand, letting populations of current pests stabilize and letting populations of current predators stabilize are not practices typically associated with classical biological control. Classical biological control focuses on adding new agents to manage pest populations rather than allowing existing populations of pests or predators to establish without intervention.

Thus, the inclusion of both options that involve allowing existing populations to stabilize indicates they do not contribute to the classical biological control method, leading to the conclusion that both scenarios, B and C, are indeed not involved in this approach.