Thoreau included the following sentence in Walden:


"There is some of the same fitness in a man's building his own house that there is in a bird's building its own nest."


Which of the following statements rephrases his literal comparison as a metaphor?


A man building his house is like a bird building his nest.

A man's house is his nest.

Every bird is an architect and builder of a nest.

Between a human house and an avian nest, there is absolutely no difference in architectural skill.