According to IS : 2720 - 1965, the composition of a dispersing solution used in pipette analysis for determining the size of particles, is

• A. sodium-hexametaphosphate 33 g, sodium carbonate 7 g and distilled water one litre
• B. sodium-hexametaphosphate 7 g, sodium carbonate 33 g and distilled water one litre
• C. sodium-hexametaphosphate 23 g, sodium carbonate 17 g and distilled water one litre
• D. none of these.