The preemption act most directly dealt with
(a) the sale of government land
(b) the right of the united states to attack nations perceived as a threat
(c) the passage of strict slave laws to suppress future slave uprisings
(d) the federal government’s right to remove native americans from
lands planned for future expansion
(e) the states’ right to nullify federal mandates

The Preemption Act most directly dealt with A) THE SALE OF GOVERNMENT LAND.

The Preemption Act of 1841 was a federal law approved on September 4, 1841. It is also known as the Distributive Preemption Act. This Act  permitted "squatters" who were living on federal government owned land to purchase up to 160 acres  at a very low price; not less than $1.25 per acre,  before the land was to be offered for sale to the general public.

The correct answer is A. The president that followed a policy of reducing the role of the federal government in managing state affairs was Ronald Reagan.

Explanation:

During his presidential campaign, Reagan declared "I believe in the rights of states" and "I think we have distorted the balance of our government by giving powers that were never believed to be given in the Constitution to the federal government." He continued promising to "restore to the states and local administrations the power that by right belongs to them."