闭合回路的磁通量φ随时间t变化的图象分别如图①-④所示，关于回路中产生的感应电动势的下列论述，其中正确的是

A．图①回路中有感应电动势且恒定不变

B．图②回路中感应电动势恒定不变

C．图③回路中0-t₁时间内的感应电动势小于t₁-t₂时间内的感应电动势

D．图④回路中感应电动势先变大，再变小

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.

The servant who carried food was a ______ man.

A. kind


B. foolish


C. clever