George Goethals was the military engineer who completed construction of the Panama Canal. The correct option among all the options given in the question is option "d". He was appointed the chief engineer of the Panama project by President Roosevelt on 26th of February in the year 1907. Goethals was absolutely determined in seeing through the job that was handed over to him by the President.
Improvement in medicine and science, this helps us live longer and therefore results in the birth of more children.
You! Your shoes are cheaper, therefore, more desirable. They save people $50!
If you are talking about them trying to expand in to present-day Canada, then it brought renewed conflict with Britain (war of 1812)
if it is towards the west, i guess it hampered technological development, because most people were moving west through the trails, instead of staying to help build up the economy
hope this helps