Which of the following is the only marsupial found on the continent?

The correct answer is the opossum, which is indeed the only marsupial found in the continental United States. Marsupials are characterized by their unique reproductive system, particularly the way they give birth to underdeveloped young that typically continue to develop in a pouch.

In North America, the Virginia opossum is the only representative of this group. Opossums are important for the ecosystem as they help control pests and carry out scavenging activities. They are also known for their ability to play dead as a defense mechanism against predators.

The other options listed are not found as native marsupials in the U.S. The raccoon, while common, is a member of the order Carnivora and is not a marsupial. The tree kangaroo is a marsupial but is native to Australia and New Guinea, not the American continent. The spelling "opossum" includes a silent 'o,' which is often omitted in casual usage, but it refers to the same creature as the option labeled without the 'o.'

Thus, in the context of the question, the opossum stands out as the only marsupial found in the continental U.S., highlighting its unique position within North American wildlife.