下列选项中属于影响导体电阻大小因素的是（　　）

A．导体两端的电压

B．导体中的电流

C．导体的材料

D．导体实际消耗的电功率

One day a businessman was going to another town to sell his goods (货物). He decided to take ten servants(仆人) with him. They would carry his goods and also some food to eat on the way. He said to one of the servants, "You are the smallest and the shortest one. You may carry the lightest load (担子). "The servant thanked him but took the biggest load. This was the bread to eat on the way.
The man said, "You’re foolish. That is the heaviest load." But the servant took up the load happily, and so they set off. After four hours they stopped for a rest. They all ate some of the bread. Then there was less bread for the servant to carry. Every time they ate some bread, the load became smaller and lighter. At the end of the trip, the servant had nothing to carry, and all the other servants still had a lot of things to carry.

On their way to the other town ______ .

A. one of the servants carried food but the others didn’t
B. no one carried food
C. all carried some food