Q$\mathrm{.}3.$ A$)$ Four soil samples loaded in saturation state till $150$kPa net vertical stress. The suction increases in sample A under the same net stress to $750$kPa, while in sample B the suction increases till $500$kPa and net stress increases to $250$kPa. In the sample $C$ the suction first increases to $500$kPa then the sample loaded to $350$kPa, while in sample $D$ the suction increases till $350$kPa and net stress increases to $250$kPa. If the $SI=1000$kPa,$=9\mathrm{.}0,r=0\mathrm{.}75,(0)=0\mathrm{.}25,k=0\mathrm{.}015,PC=20$kPa, describe the state of each point $($elastic or plastic$)$ regarding to BBM$,$ support you answer with equations.