According to paragraph 6, which of the following was true of the hare population cycle in Krebs's experiment? A. The effects of providing food while at the same time introducing predators cancelled each other, so there was no cycle. B. The cycle existed when either the food supply was limited or there were predators. C. There was a cycle when there were no predators and food was supplied. D. If the hares had places to hide from the lynx, the hare population increased tenfold and then remained at that level.