Read this excerpt from The Call of the Wild by Jack London. Then where could they possibly be? With drooping tail and shivering body, very forlorn indeed, he aimlessly circled the tent. Suddenly the snow gave way beneath his fore legs and he sank down. Something wriggled under his feet. He sprang back, bristling and snarling, fearful of the unseen and unknown. But a friendly little yelp reassured him, and he went back to investigate. A whiff of warm air ascended to his nostrils, and there, curled up under the snow in a snug ball, lay Billee. . . . Another lesson. So that was the way they did it, eh? Buck confidently selected a spot, and with much fuss and waste effort proceeded to dig a hole for himself. In a trice the heat from his body filled the confined space and he was asleep. What theme does the excerpt convey? Adaptability is key to success. Friendship leads to fulfillment. Sleep is essential for survival. Teamwork encourages specialization