Read the excerpt from "On Becoming an Inventor" by Dean Kamen. My next challenge was that I wanted to make things out of metal, so I became interested in how to use a lathe, a milling machine, and so on. I went to buy this new equipment I thought I'd need and met a man who had a machine shop of his own who was about to retire and move to Florida. He allowed me to visit him after school and on weekends to observe how he used all his tools. I was hooked. When he retired I bought not only all his big equipment but all his little toolboxes as well--they were treasures!

I decided to put his entire machine shop in our basement, but there were two problems... One, his shop wouldn't fit in our basement, and two, there was no way the lathe, weighing fifteen hundred pounds, and the milling machine, weighing two thousand pounds, could be carried into the basement. I solved this problem by hiring a contractor to dig a large hole, break open a wall of the basement, enclose the addition with concrete, and add a roof that could be used for building an outside deck to the house. I also enlarged my mother's kitchen and pantry. I now had the entire machine shop in our basement. At the time I was making enough money from my electronic devices to pay for all of this.

Which detail best supports Kamen’s opinion that he was hooked on making things out of metal?

He allowed me to visit him after school and on weekends to observe how he used all his tools.
When he retired I bought not only all his big equipment but all his little toolboxes as well—they were treasures!
One, his shop wouldn't fit in our basement, and two, there was no way the lathe, weighing fifteen hundred pounds, and the milling machine . . . could be carried into the basement.
At the time I was making enough money from my electronic devices to pay for all of this.