Given a scientific question, generate a correct answer to it.

Input: Consider Input: Cytokinins promote cell division and prevent what?

Output: senescence

Input: Consider Input: Radioisotopes may vary greatly in their rate of decay, decaying faster if their nuclei are more what?

Output: unstable

Input: Consider Input: What are formed when primary pollutants interact with sunlight, air, or each other?
Output: secondary pollutants