A more or less circular ring of mushrooms appears in your yard, apparently overnight. The circle is...?

Question

A more or less circular ring of mushrooms appears in your yard, apparently overnight. The circle is several yards in diameter. The most likely explanation for this circle of mushrooms is that

A. mushroom spores were dropped by a circling bird, thus explaining the circular shape of the group of mushrooms.

B. the mushroom plants in the center of the circle have been eaten by herbivores.

C. the mushrooms are all part of the same plant, with mycelia radiating out from the location of a germinated spore.

D. one mushroom in the circle reproduced sexually to make all the other mushrooms in the circle.

E. a circle is nature's most perfect shape for asexual reproduction structures.

Answer 1

C. is correct.

the ring gets bigger all the time until such time as the mushrooms cover a large area and it no longer looks like a ring.

They used to be known as fairy circles.

See this link

http://en.wikipedia.org/wiki/Fairy_rings

Answer 2

an entry portal to the faery realm...