the answer is d. It basically wanted to wanted to "acclimatize" Native Americans to white culture. it forced 160-acre homesteads into the hands of individual Indians and their families with the promise of future citizenship.
The economy you described in your question is called a market economy. It has free markets and the production of goods and services are determined by the consumers.
The enlightenment started in 1715 and ended in 1789 so it lasted 74 years
He conserved forests and wildlife after Harold Ickes convinced him to build a wildlife reserve.
