Exempted from imposition of the weight distance tax is the use of the highways of this state by:

A. school buses;

B. buses used exclusively for the transportation of agricultural laborers; C. buses operated by religious or nonprofit charitable organizations; and

D. commercial motor carrier vehicles as defined in Subsection B of Section 7-15-2.1 N.M. Stat. Ann. while operating exclusively within ten miles of a border with Mexico in conjunction with crossing the border with Mexico.