Around the time of the roman empire the terms inch, foot, and yard were refined. what was the length of a foot based on?

 The Romans measured the feet of the average person’s foot and it turned out to be 12 inches.

The romans tested everyone's feet and the average was about 12 inches.

the doctrine of nullification recommended that states living inside the union have the one-sided, inalienable ideal to void any law made by the national government that could be esteemed illegal.

the united states was shaped based on a general agreement among its individual states. hence, it is inferred that under the hypothesis of invalidation, since the states are the establishment of the union, they have the ability to referee and disprove unlawful laws.

if i am correct the answer is going to be a) the federal program of reconstruction ended.