I think it will most likely be A
An opportunity is something that is given to you through work or just chance, a trade off is something that is pre determined for a food or service that is decided is of the same value
<span>Herbert Spencer was the philosopher and scientist of the XIX, who applied the studies of evolution to the branch of biology and psychology, among others. Herbert Spencer was an English philosopher and sociologist. He developed an idea of evolution as the progressive development of the physical world, biological organisms, and the mind.</span>