Define the concentration measurements of parts per million

Explanation:

Parts per million (ppm) is the number of units of mass of a contaminant per million units of total mass

ppm (or ppmm) is used to measure the concentration of a contaminant in soils and sediments. In that case 1 ppm equals 1 mg of substance per kg of solid (mg/kg).

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be