Martin Keeps a Worm Bin in His Basement Because the Worms

Martin keeps a worm bin in his basement because the worms need cooler temperatures to survive. He feeds them about one pound of kitchen scraps each week. One summer the temperatures rose above the optimal temperature for the red worms ~ 85°F) and many in his colony died. However, those that survive continued to reproduce and within six months his colony was again thriving. The next summer, unusually warm temperatures again cause the basement temperatures to rise above 85°F for two 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.