What did President Lincoln do on September 22, 1862?

announcing on September 22, 1862, that if the rebels did not end the fighting and rejoin the Union by January 1, 1863, all slaves in the rebellious states would be free.

Explanation:

answer:

d. because dr. laguardia selected a widely used measure, his study generalizes to has strong external validity. external validity has limited external validity. other applications of this measure.

the widely used measure that he applied to his experiment was the benton facial recognition test. it employed on to football players and as result, only players who suffered brain concussions did not pas this test. and although it has an external validity, it is limited because it isn't general to apply to other population.

is there a year set? the question is incomplete