Answer:
D) parallelism
Explanation:
Parallelism is a figure of speech in which two or more elements of a sentence (or series of sentences) have the same grammatical structure.
The lines "Fondly do we hope--fervently do we pray" and "With malice toward none; with charity for all" clearly show the repetition of similar grammatical constructions.
According to Pi, a zookeeper will know he or she has created a healthy environment for the animals WHEN THE ANIMALS REPRODUCE.
For animals to reproduce and give birth to young ones, many things has to be in place, such as suitable partners, right environment, right food, etc. Animals naturally reproduce when the environment is favorable unto them. Thus, reproduction of animals in the zoo shows that the right environment has been created for the animals.