Final answer:
The Organism A population is likely to be greatest in June due to favorable conditions for reproduction and a higher turnover rate during the summer months.
Step-by-step explanation:
The Organism A population is likely to be greatest in Choice A: June.
This is because the Organism A population experiences a rapid growth curve during the summer months. As the weather gets warmer, the conditions become more favorable for reproduction, increasing in population size. Additionally, Organism A may have a shorter lifespan, leading to a higher turnover rate and an overall larger population during this time. Hence June is the correct option.