There are times when the President refuses to spend money that has been appropriated by Congress. Which principle does this align with? My options are popular sovereignty checks and balances separation of powers and federalism

Impoundment is an act by a President of the United States of not spending money that has been appropriated by the U.S. Congress. Thomas Jefferson was the first president to exercise the power of impoundment in 1801. ... The president's ability to indefinitely reject congressionally approved spending was thus removed.

i think they would live in caves or natural tunnels

brainliest is someone you pick by simply clicking a button. it only shows up if there are two people that answered your question, then you decide who answer more accurately with detail and explanation and you give that person the title "brainliest".

i hope this your understandings.