What does Congress rely on to stretch its powers?
a. The enumerated powers
b. The elastic clause
c. Bills of attainder
d. Ex post facto laws

Clause 18, the elastic clause, allows Congress to stretch its powers to meet the new needs. The implied powers gives Congress the authority to do whatever is necessary and proper to carry out its expected powers. Why do you think that the House rarely impeached a to government official?

So the answer is B- The elastic Clause!

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.