Which of the following is an example of a president acting despite the constitutional authority of congress to act on the matter at hand?

these presidents have used a line-item veto over several decades to save millions of dollars without asking the permission of congress first.
these presidents have sent troops to resolve conflicts overseas without waiting for the congress to declare an official act of war first.
these presidents have broadcast the state of the union address over radio and television instead of presenting it to congress first.
these presidents have demonstrated an increasing use of issue congruence without congress approving these measures first.

These presidents have sent troops to resolve conflicts overseas without waiting for the Congress to declare an official act of war first.

Explanation:

The president can only declare war on another country with congressional authorization. To do so without this endorsement is considered a liability crime under national law - and this type of crime can lead to impeachment.

Under the law the president cannot "declare" war, send topas abroad except in cases of foreign invasion or aggression, or make peace without authorization from the National Congress. From this we can conclude that presidents can send troops to resolve conflicts abroad without waiting for Congress to first declare an official act of war, that is, they can only send troops on a peace mission.

early human migrations are the earliest migrations and expansions of archaic and modern humans across continents and are believed to have begun approximately 2 million years ago with the out of africa migration of homo erectus. this initial migration was followed by other archaic humans including h. heidelbergensis, which lived around 500,000 years ago and was the likely ancestor of both denisovans and neanderthals. early hominids were said to have "crossed land bridges that were eventually covered in water" .

within africa, homo sapiens dispersed around the time of its speciation, roughly 300,000 years ago.the "recent african origin" paradigm suggests that the anatomically modern humans outside of africa descend from a population of homo sapiens migrating from east africa roughly 70,000 years ago and spreading along the southern coast of asia and to oceania before 50,000 years ago. modern humans spread across europe about 40,000 years ago.

the migrating modern human populations are known to have interbred with local varieties of archaic humans, so that contemporary human populations are descended in small part (below 10% contribution) from regional varieties of archaic humans.

after the last glacial maximum, north eurasian populations migrated to the americas about 20,000 years ago. northern eurasia was peopled after 12,000 years ago, in the beginning holocene. arctic canada and greenland were reached by the paleo-eskimo expansion around 4,000 years ago. finally, polynesia was peopled after 2,000 years ago, by the austronesian expansion.

the roman army grew in size and became dominant in the mediterranean region.