Read the excerpt from The Boy Who Harnessed the Wind by William Kamkwamba.

I could get money by working ganyu. At the time, guys were making one hundred kwacha unloading trucks at CHiPiKU store, so I headed there. If I worked a whole week, I could have enough. I waited outside the store all morning and into the afternoon. The sun was dreadful, and I had no water. Finally the owner walked outside and saw me.

"Why are you standing here?" he said.

"Waiting for trucks."

"Trucks come every day," he said. "Except Monday."

It was Monday.

That night at home, I hit upon another idea. The bicycle dynamo was the ideal generator for the bigger windmill I wanted to create, and at some point I'd have to work for the money to buy it. But for this experimental model, I could get by with using a much smaller generator, and I knew just where to find that.

Which character trait do the details in the excerpt reveal about Kamkwamba?

greed
kindness
persistence
laziness