(a) The tick eradication area is composed of counties and parts of counties designated for tick eradication under Section 167.006 of this code.
(b) The free area and the inactive quarantine area are composed of counties and parts of counties designated by the commission to be part of the applicable area.
(c) The commission may transfer a county or part of a county from the tick eradication area, the free area, or the inactive quarantine area to another type of area as the commission considers advisable or necessary.