With better plows, increased plowing, and more scientific methods of farming,

The complete question is given below:

With better plows, increased plowing, and more scientific methods of farming:

a. Congress immediately passed new environmental protection laws

b. did not impact settlers’ desires to move West

c. settlers shared improved farming techniques with Native Americans  

d. settlers thought the West became a more desirable place to make a new start.

Option D, settlers thought the West became a more desirable place to make a new start, is the right answer.

Explanation:

Following their independence from the colonial rule, the thirteen states of America began to expand their territories and thus started expanding into the western frontier. The U.S. gained a huge area of land from the Louisiana purchase. The land from the Louisiana Purchase doubled the size of land for the United States. Since many of the people wanted to live better lives they regarded West as a place to make a new start.