$\backslash$table$[[$Problem$,,,],[\backslash$table$[[$Soil$],[$Sample$]],$LL$,$PL$,],[$A$,44,21,],[$B$,$Non$-,$astic,$],[$C$,16,11,],[$D$,60,33,],[$E$,40,30,],[$F$,25,19,],[$G$,$Non$-,$astic,$]]$

Grain size distribution analyses have been performed on several soil samples, and the results of these tests are shown as curves A$-$G in the following figure. The results of the Atterberg limits tests are also summarized below. $($a$)$ Classify all these soil samples according to both ASTM$-$CS and AASHTO. $($b$)$ Discuss the suitability of each soil as a subgrade material.