Which of the following is example of a reserved power

Assuming that this is referring to the same list of options that was posted before with this question, the correct response would be "collecting state taxes", since this power, because it's not specifically given to Congress by the Constitution, is "reserved" for the states. 

The statistics for the eastern war are grim. more than three-million men died in the fighting, more than nine-million men were wounded, and every major country which participated lost its form of government.