The act of directing, ordering, or controlling by virtue of explicit statutory, regulatory, or delegated authority at the field level is referred to as:
a. direction
b. leadership
c. command
d. coordination

The act of directing, ordering, or controlling by virtue of explicit statutory, regulatory, or delegated authority at the field level is referred to as "command," since this can be exercised at a variety of different power levels. 

Cherokee  removal, part of the trail of tears, refers to the  forced  relocation between 1836 and 1839 of thecherokee  nation from  their lands ingeorgia, south carolina, north carolina, tennessee, texas, and alabama to the indian territory (present day oklahoma)  in  the thenwestern united states, and the resultant deaths