How did the Columbian exchange change the way we eat?

Look at this photograph taken during the battle of guadalcanal

This was an order issued during the civil war by president lincoln ending slavery in the confederate states

Which of these was one of the most important aspects of washington's presidency a. he did not consider how his actions would affect later presidents b. he came to believe that political parties would be good for the country. c. he insisted that congress make specific rules about the duties of the president d. he did not take advantage of the opportunity to keep the power the country offered him.