Answer:
The correct answer is option D. "Put soil, water, many plants, and a few insects in a sealed, clear plastic aquarium. Place it in an area with indirect sunlight".
Step-by-step explanation:
One characteristic that helps a self-sustaining ecosystem, or vivarium, to last as long as possible without no additional care is isolating it form external factors that could alter its equilibrium. The option that accomplish this characteristic is to put soil, water, many plants, and a few insects in a sealed, clear plastic aquarium and place it in an area with indirect sunlight. Also, this vivarium has the elements needed for plants to grow, and a few insects that function as primary consumers to naturally select the strongest plants.