Milkweed plants are the only source of energy for the monarch butterfly caterpillars. Aphids are insects that insert their mouthparts into the milkweed plant and out the liquid inside the plant, causing drastic declines in the population of milkweed plants.

How could the aphid population on the milkweed plant impact the population of monarch butterflies?
Group of answer choices

The number of monarch butterflies will stay the same because butterflies reproduce so rapidly their populations can withstand most food shortages.

The number of monarch butterflies will increase because their reproduction rate will increase to ensure some individuals survive.

The number of monarch butterflies will decrease because their caterpillars will not have enough food.

The number of monarch butterflies will stay the same because their caterpillars will begin consuming nectar from different types of flowers.

The correct answer is: The number of monarch butterflies will decrease because their caterpillars will not have enough food.

Explanation: The passage states that milkweed plants are the primary source of energy for monarch butterfly caterpillars. If the aphid population on the milkweed plants increases and causes drastic declines in the milkweed plant population, there will be less food available for monarch butterfly caterpillars. As a result, the caterpillars will not have enough food to survive and develop into butterflies. Therefore, the population of monarch butterflies will decrease.