Martin Keeps a Worm Bin in His Basement Because They

Martin keeps a worm bin in his basement because they need cooler temperatures to survive. He feeds them about 1 pound of kitchen scraps each week. One summer the temperatures rise above the optimal temperature for the red worms (~ 85°F) and many in his colony die. However, those that survive continue to reproduce and within 6 months his colony is again thriving. The next summer, unusually warm temperatures again cause the basement temperatures to rise above 85°F for 2 days in a row. Surprisingly, Martin noticed that only a small portion of the worm colony died. What is the best explanation for this?

A) After the first summer a new species of worm evolved.
B) The worms sensed that the temperature was going to be hot in the future and adapted.
C) The worms learned how to tolerate higher temperatures.
D) The worms surviving the first year had a higher heat tolerance and passed this trait to their offspring.
E) Worms are insensitive to heat changes.