Answer:
The correct answer is - "is this factor decreasing the population growth rate in the environment?".
Step-by-step explanation:
When a factor or resource in the environment causes the decreases or lowers the population growth rate, such factors known as the limiting factors. Limiting factors can be lower food resources, higher competition, lower birth rates, higher death rates, and many other factors.
Thus, the correct question should ask about the limiting factors that are affecting the monarch population would be - "is this factor decreasing the population growth rate in the environment?".