What was the key to american security during the nineteenth century?

i am not 100% positive but i think it is is b. both are non-partisan jobs

i am pretty sure that members of congress have term limits, can be impeached, and are nominated through direct popular vote.

during the 20th century, the role of the vice president has evolved into more of an executive branch position. now, the vice president is usually seen as an integral part of a president's administration and presides over the senate only on ceremonial occasions or when a tie-breaking vote may be needed.