The modern united states regime shares power between the states and national government, makin it an example of which type of system?

The correct answer is - federal system.

The United States are a country in which the federal system is the one in place. This system practically means that the power is shared between the central government and the federal states. The central government is still the dominant center of power, but the federal states also are able to function in a manner they want to, to a certain level of course. The reason why is this type of power in force in the United States is mainly because the country has become what it is with the unification of the states. There's 52 federal states in the United States, and most of them were self governed in big portion of the American history, so when they decided to create one big country, the condition was that they still have power in the federal states.

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering