Eli Keeps a Worm Bin in His Basement Because the Worms

Eli 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 thriving again. The following summer, unusually warm temperatures once again resulted in the basement temperatures rising above 85°F. Surprisingly, Eli 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 that survived the first summer had a higher heat tolerance and passed this trait on to their offspring.
E) Temperature and worm survival are not related.