Final answer:
The Danaus Plexippus butterfly is known as the Monarch butterfly, which is famous for its long migratory journey. The Viceroy butterfly mimics the Monarch but belongs to a different genus.
Step-by-step explanation:
The correct answer to the question is a) Monarch. The Danaus Plexippus butterfly is more commonly known as the Monarch butterfly. This species is renowned for its incredible migratory pattern, where it can fly up to 3,000 miles from North America to Mexico for the winter. Although the question might also allude to an emperor or a king, in the context of butterflies, the correct association is with the Monarch butterfly. It's interesting to note the Viceroy butterfly (Limenitis archippus), which is a mimic of the Monarch but belongs to a different genus, indicating a more distant relation. Both the Monarch and the Viceroy butterflies have impressive and distinct characteristics worthy of study.