Read the excerpt from "On Becoming An Inventor" by Dean Kamen. From this well-stocked basement came a whole new set of really neat projects. My younger brother, Mitch, and his friends, as well as some of my own friends, would come after school to help. At sixteen I was now a young entrepreneur, paying them for their help. I was surprised by the number of orders I was getting for more and more equipment. Soon I didn't have time to build and design new things. Giving over this work to other kids gave me more time to do what I wanted to do. This went on after school and all summer long.
Which of the following is a signal word from this excerpt that shows an opinion?
A. neat
B. younger
C. entrepreneur
D. equipment