The correct answer is option A. The passage clearly talks about Marsupials since it mentions its characteristcs such as their physical appearance, way of living and place, among other details. Although it talks about kangoroos mostly, it also mentions and characterizes another marsupial, that is Wallabies. Option B does not capture the main idea of the passage, since it talks about both kangoroos and other marsupials. Options C and D refer to specific features of kangoroos, they are too specific to be considered a summary of the main idea of the passage.