A given cohesionless soil has emax $=0\mathrm{.}85$ and emin $=0\mathrm{.}50.$ In the field, the soil is compacted to a mass density of $1800$ kg$/$m at a water content of $8\%.$ Take the mass density of water as $1000$ kg$/$m and Gs as $2\mathrm{.}7.$ The relative density $($in $\%)$ of the soil is a$)56\mathrm{.}43$ b$)60\mathrm{.}25$ c$)62\mathrm{.}87$ d$)65\mathrm{.}71$