2. what issue was at the root of the nullification crisis?
a the president wanted to nullify an act of congress.
b states wanted to nullify federal laws that they deemed
unconstitutional
c states wanted to nullify the constitution.
d the federal government wanted to nullify the power of the states.

The root issue for the nullification crisis was:

B States wanted to nullify federal laws that they deemed  unconstitutional

Explanation:

The Nullification crisis has its roots in the refusal to collect tariffs between 1828 and 1832 by the state of South Carolina.

the berlin blockade was an international crisis that arose from an attempt by the soviet union, in 1948–49, to force the western allied powers (the united states, the united kingdom, and france) to abandon their post-world war ii jurisdictions in west berlin. in march 1948 the allied powers decided to unite their different occupation zones of germany into a single economic unit. in protest, the soviet representative withdrew from the allied control council. coincident with the introduction of a new deutsche mark in west berlin (as throughout west germany), which the soviets regarded as a violation of agreements with the allies, the soviet occupation forces in eastern germany began a blockade of all rail, road, and water communications between berlin and the west. on june 24 the soviets announced that the four-power administration of berlin had ceased and that the allies no longer had any rights there.

i also think he is correct. i believe they came to washington to protest their rights.